Граф коммитов

501 Коммитов

Автор SHA1 Сообщение Дата
Nikita Zhandarovich 89969ffbeb net/9p: fix uninit-value in p9_client_rpc()
commit 25460d6f39024cc3b8241b14c7ccf0d6f11a736a upstream.

Syzbot with the help of KMSAN reported the following error:

BUG: KMSAN: uninit-value in trace_9p_client_res include/trace/events/9p.h:146 [inline]
BUG: KMSAN: uninit-value in p9_client_rpc+0x1314/0x1340 net/9p/client.c:754
 trace_9p_client_res include/trace/events/9p.h:146 [inline]
 p9_client_rpc+0x1314/0x1340 net/9p/client.c:754
 p9_client_create+0x1551/0x1ff0 net/9p/client.c:1031
 v9fs_session_init+0x1b9/0x28e0 fs/9p/v9fs.c:410
 v9fs_mount+0xe2/0x12b0 fs/9p/vfs_super.c:122
 legacy_get_tree+0x114/0x290 fs/fs_context.c:662
 vfs_get_tree+0xa7/0x570 fs/super.c:1797
 do_new_mount+0x71f/0x15e0 fs/namespace.c:3352
 path_mount+0x742/0x1f20 fs/namespace.c:3679
 do_mount fs/namespace.c:3692 [inline]
 __do_sys_mount fs/namespace.c:3898 [inline]
 __se_sys_mount+0x725/0x810 fs/namespace.c:3875
 __x64_sys_mount+0xe4/0x150 fs/namespace.c:3875
 do_syscall_64+0xd5/0x1f0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

Uninit was created at:
 __alloc_pages+0x9d6/0xe70 mm/page_alloc.c:4598
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 alloc_slab_page mm/slub.c:2175 [inline]
 allocate_slab mm/slub.c:2338 [inline]
 new_slab+0x2de/0x1400 mm/slub.c:2391
 ___slab_alloc+0x1184/0x33d0 mm/slub.c:3525
 __slab_alloc mm/slub.c:3610 [inline]
 __slab_alloc_node mm/slub.c:3663 [inline]
 slab_alloc_node mm/slub.c:3835 [inline]
 kmem_cache_alloc+0x6d3/0xbe0 mm/slub.c:3852
 p9_tag_alloc net/9p/client.c:278 [inline]
 p9_client_prepare_req+0x20a/0x1770 net/9p/client.c:641
 p9_client_rpc+0x27e/0x1340 net/9p/client.c:688
 p9_client_create+0x1551/0x1ff0 net/9p/client.c:1031
 v9fs_session_init+0x1b9/0x28e0 fs/9p/v9fs.c:410
 v9fs_mount+0xe2/0x12b0 fs/9p/vfs_super.c:122
 legacy_get_tree+0x114/0x290 fs/fs_context.c:662
 vfs_get_tree+0xa7/0x570 fs/super.c:1797
 do_new_mount+0x71f/0x15e0 fs/namespace.c:3352
 path_mount+0x742/0x1f20 fs/namespace.c:3679
 do_mount fs/namespace.c:3692 [inline]
 __do_sys_mount fs/namespace.c:3898 [inline]
 __se_sys_mount+0x725/0x810 fs/namespace.c:3875
 __x64_sys_mount+0xe4/0x150 fs/namespace.c:3875
 do_syscall_64+0xd5/0x1f0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

If p9_check_errors() fails early in p9_client_rpc(), req->rc.tag
will not be properly initialized. However, trace_9p_client_res()
ends up trying to print it out anyway before p9_client_rpc()
finishes.

Fix this issue by assigning default values to p9_fcall fields
such as 'tag' and (just in case KMSAN unearths something new) 'id'
during the tag allocation stage.

Reported-and-tested-by: syzbot+ff14db38f56329ef68df@syzkaller.appspotmail.com
Fixes: 348b59012e ("net/9p: Convert net/9p protocol dumps to tracepoints")
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru>
Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com>
Cc: stable@vger.kernel.org
Message-ID: <20240408141039.30428-1-n.zhandarovich@fintech.ru>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-16 13:39:58 +02:00
Fedor Pchelkin 4431cf7c33 net: 9p: avoid freeing uninit memory in p9pdu_vreadf
commit ff49bf1867578f23a5ffdd38f927f6e1e16796c4 upstream.

If some of p9pdu_readf() calls inside case 'T' in p9pdu_vreadf() fails,
the error path is not handled properly. *wnames or members of *wnames
array may be left uninitialized and invalidly freed.

Initialize *wnames to NULL in beginning of case 'T'. Initialize the first
*wnames array element to NULL and nullify the failing *wnames element so
that the error path freeing loop stops on the first NULL element and
doesn't proceed further.

Found by Linux Verification Center (linuxtesting.org).

Fixes: ace51c4dd2 ("9p: add new protocol support code")
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Message-ID: <20231206200913.16135-1-pchelkin@ispras.ru>
Cc: stable@vger.kernel.org
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-05 15:13:34 +01:00
Dominique Martinet e6fbad3cc8 9p: v9fs_listxattr: fix %s null argument warning
[ Upstream commit 9b5c6281838fc84683dd99b47302d81fce399918 ]

W=1 warns about null argument to kprintf:
In file included from fs/9p/xattr.c:12:
In function ‘v9fs_xattr_get’,
    inlined from ‘v9fs_listxattr’ at fs/9p/xattr.c:142:9:
include/net/9p/9p.h:55:2: error: ‘%s’ directive argument is null
[-Werror=format-overflow=]
   55 |  _p9_debug(level, __func__, fmt, ##__VA_ARGS__)
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Use an empty string instead of :
 - this is ok 9p-wise because p9pdu_vwritef serializes a null string
and an empty string the same way (one '0' word for length)
 - since this degrades the print statements, add new single quotes for
xattr's name delimter (Old: "file = (null)", new: "file = ''")

Link: https://lore.kernel.org/r/20231008060138.517057-1-suhui@nfschina.com
Suggested-by: Su Hui <suhui@nfschina.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Acked-by: Christian Schoenebeck <linux_oss@crudebyte.com>
Message-ID: <20231025103445.1248103-2-asmadeus@codewreck.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-28 16:56:19 +00:00
Marco Elver a18be976be 9p/trans_fd: Annotate data-racy writes to file::f_flags
[ Upstream commit 355f074609dbf3042900ea9d30fcd2b0c323a365 ]

syzbot reported:

 | BUG: KCSAN: data-race in p9_fd_create / p9_fd_create
 |
 | read-write to 0xffff888130fb3d48 of 4 bytes by task 15599 on cpu 0:
 |  p9_fd_open net/9p/trans_fd.c:842 [inline]
 |  p9_fd_create+0x210/0x250 net/9p/trans_fd.c:1092
 |  p9_client_create+0x595/0xa70 net/9p/client.c:1010
 |  v9fs_session_init+0xf9/0xd90 fs/9p/v9fs.c:410
 |  v9fs_mount+0x69/0x630 fs/9p/vfs_super.c:123
 |  legacy_get_tree+0x74/0xd0 fs/fs_context.c:611
 |  vfs_get_tree+0x51/0x190 fs/super.c:1519
 |  do_new_mount+0x203/0x660 fs/namespace.c:3335
 |  path_mount+0x496/0xb30 fs/namespace.c:3662
 |  do_mount fs/namespace.c:3675 [inline]
 |  __do_sys_mount fs/namespace.c:3884 [inline]
 |  [...]
 |
 | read-write to 0xffff888130fb3d48 of 4 bytes by task 15563 on cpu 1:
 |  p9_fd_open net/9p/trans_fd.c:842 [inline]
 |  p9_fd_create+0x210/0x250 net/9p/trans_fd.c:1092
 |  p9_client_create+0x595/0xa70 net/9p/client.c:1010
 |  v9fs_session_init+0xf9/0xd90 fs/9p/v9fs.c:410
 |  v9fs_mount+0x69/0x630 fs/9p/vfs_super.c:123
 |  legacy_get_tree+0x74/0xd0 fs/fs_context.c:611
 |  vfs_get_tree+0x51/0x190 fs/super.c:1519
 |  do_new_mount+0x203/0x660 fs/namespace.c:3335
 |  path_mount+0x496/0xb30 fs/namespace.c:3662
 |  do_mount fs/namespace.c:3675 [inline]
 |  __do_sys_mount fs/namespace.c:3884 [inline]
 |  [...]
 |
 | value changed: 0x00008002 -> 0x00008802

Within p9_fd_open(), O_NONBLOCK is added to f_flags of the read and
write files. This may happen concurrently if e.g. mounting process
modifies the fd in another thread.

Mark the plain read-modify-writes as intentional data-races, with the
assumption that the result of executing the accesses concurrently will
always result in the same result despite the accesses themselves not
being atomic.

Reported-by: syzbot+e441aeeb422763cc5511@syzkaller.appspotmail.com
Signed-off-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/r/ZO38mqkS0TYUlpFp@elver.google.com
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Message-ID: <20231025103445.1248103-1-asmadeus@codewreck.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-28 16:56:19 +00:00
Hangyu Hua 855d6fb2cc 9p/net: fix possible memory leak in p9_check_errors()
[ Upstream commit ce07087964208eee2ca2f9ee4a98f8b5d9027fe6 ]

When p9pdu_readf() is called with "s?d" attribute, it allocates a pointer
that will store a string. But when p9pdu_readf() fails while handling "d"
then this pointer will not be freed in p9_check_errors().

Fixes: 51a87c552d ("9p: rework client code to use new protocol support functions")
Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com>
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Message-ID: <20231027030302.11927-1-hbh25y@gmail.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:08:26 +01:00
Dominique Martinet 20d449a087 9p: virtio: make sure 'offs' is initialized in zc_request
[ Upstream commit 4a73edab69 ]

Similarly to the previous patch: offs can be used in handle_rerrors
without initializing on small payloads; in this case handle_rerrors will
not use it because of the size check, but it doesn't hurt to make sure
it is zero to please scan-build.

This fixes the following warning:
net/9p/trans_virtio.c:539:3: warning: 3rd function call argument is an uninitialized value [core.CallAndMessage]
                handle_rerror(req, in_hdr_len, offs, in_pages);
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-19 12:22:27 +02:00
Zheng Wang e35ae49bc1 9p/xen : Fix use after free bug in xen_9pfs_front_remove due to race condition
[ Upstream commit ea4f100940 ]

In xen_9pfs_front_probe, it calls xen_9pfs_front_alloc_dataring
to init priv->rings and bound &ring->work with p9_xen_response.

When it calls xen_9pfs_front_event_handler to handle IRQ requests,
it will finally call schedule_work to start the work.

When we call xen_9pfs_front_remove to remove the driver, there
may be a sequence as follows:

Fix it by finishing the work before cleanup in xen_9pfs_front_free.

Note that, this bug is found by static analysis, which might be
false positive.

CPU0                  CPU1

                     |p9_xen_response
xen_9pfs_front_remove|
  xen_9pfs_front_free|
kfree(priv)          |
//free priv          |
                     |p9_tag_lookup
                     |//use priv->client

Fixes: 71ebd71921 ("xen/9pfs: connect to the backend")
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-04-20 12:13:53 +02:00
Eric Van Hensbergen 0fc608a115 net/9p: fix bug in client create for .L
[ Upstream commit 3866584a1c ]

We are supposed to set fid->mode to reflect the flags
that were used to open the file.  We were actually setting
it to the creation mode which is the default perms of the
file not the flags the file was opened with.

Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
Reviewed-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-22 13:31:31 +01:00
Zhengchao Shao 2721d96668 9p/rdma: unmap receive dma buffer in rdma_request()/post_recv()
[ Upstream commit 74a25e6e91 ]

When down_interruptible() or ib_post_send() failed in rdma_request(),
receive dma buffer is not unmapped. Add unmap action to error path.
Also if ib_post_recv() failed in post_recv(), dma buffer is not unmapped.
Add unmap action to error path.

Link: https://lkml.kernel.org/r/20230104020424.611926-1-shaozhengchao@huawei.com
Fixes: fc79d4b104 ("9p: rdma: RDMA Transport Support for 9P")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 13:57:29 +01:00
Juergen Gross 8d3fc907d0 9p/xen: fix connection sequence
[ Upstream commit c15fe55d14 ]

Today the connection sequence of the Xen 9pfs frontend doesn't match
the documented sequence. It can work reliably only for a PV 9pfs device
having been added at boot time already, as the frontend is not waiting
for the backend to have set its state to "XenbusStateInitWait" before
reading the backend properties from Xenstore.

Fix that by following the documented sequence [1] (the documentation
has a bug, so the reference is for the patch fixing that).

[1]: https://lore.kernel.org/xen-devel/20230130090937.31623-1-jgross@suse.com/T/#u

Link: https://lkml.kernel.org/r/20230130113036.7087-3-jgross@suse.com
Fixes: 868eb12273 ("xen/9pfs: introduce Xen 9pfs transport driver")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 13:57:29 +01:00
Juergen Gross fc772313f2 9p/xen: fix version parsing
[ Upstream commit f1956f4ec1 ]

When connecting the Xen 9pfs frontend to the backend, the "versions"
Xenstore entry written by the backend is parsed in a wrong way.

The "versions" entry is defined to contain the versions supported by
the backend separated by commas (e.g. "1,2"). Today only version "1"
is defined. Unfortunately the frontend doesn't look for "1" being
listed in the entry, but it is expecting the entry to have the value
"1".

This will result in failure as soon as the backend will support e.g.
versions "1" and "2".

Fix that by scanning the entry correctly.

Link: https://lkml.kernel.org/r/20230130113036.7087-2-jgross@suse.com
Fixes: 71ebd71921 ("xen/9pfs: connect to the backend")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 13:57:28 +01:00
Schspa Shi 1cabce5662 9p: set req refcount to zero to avoid uninitialized usage
commit 26273ade77 upstream.

When a new request is allocated, the refcount will be zero if it is
reused, but if the request is newly allocated from slab, it is not fully
initialized before being added to idr.

If the p9_read_work got a response before the refcount initiated. It will
use a uninitialized req, which will result in a bad request data struct.

Here is the logs from syzbot.

Corrupted memory at 0xffff88807eade00b [ 0xff 0x07 0x00 0x00 0x00 0x00
0x00 0x00 . . . . . . . . ] (in kfence-#110):
 p9_fcall_fini net/9p/client.c:248 [inline]
 p9_req_put net/9p/client.c:396 [inline]
 p9_req_put+0x208/0x250 net/9p/client.c:390
 p9_client_walk+0x247/0x540 net/9p/client.c:1165
 clone_fid fs/9p/fid.h:21 [inline]
 v9fs_fid_xattr_set+0xe4/0x2b0 fs/9p/xattr.c:118
 v9fs_xattr_set fs/9p/xattr.c:100 [inline]
 v9fs_xattr_handler_set+0x6f/0x120 fs/9p/xattr.c:159
 __vfs_setxattr+0x119/0x180 fs/xattr.c:182
 __vfs_setxattr_noperm+0x129/0x5f0 fs/xattr.c:216
 __vfs_setxattr_locked+0x1d3/0x260 fs/xattr.c:277
 vfs_setxattr+0x143/0x340 fs/xattr.c:309
 setxattr+0x146/0x160 fs/xattr.c:617
 path_setxattr+0x197/0x1c0 fs/xattr.c:636
 __do_sys_setxattr fs/xattr.c:652 [inline]
 __se_sys_setxattr fs/xattr.c:648 [inline]
 __ia32_sys_setxattr+0xc0/0x160 fs/xattr.c:648
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

Below is a similar scenario, the scenario in the syzbot log looks more
complicated than this one, but this patch can fix it.

     T21124                   p9_read_work
======================== second trans =================================
p9_client_walk
  p9_client_rpc
    p9_client_prepare_req
      p9_tag_alloc
        req = kmem_cache_alloc(p9_req_cache, GFP_NOFS);
        tag = idr_alloc
        << preempted >>
        req->tc.tag = tag;
                            /* req->[refcount/tag] == uninitialized */
                            m->rreq = p9_tag_lookup(m->client, m->rc.tag);
                              /* increments uninitalized refcount */

        refcount_set(&req->refcount, 2);
                            /* cb drops one ref */
                            p9_client_cb(req)
                            /* reader thread drops its ref:
                               request is incorrectly freed */
                            p9_req_put(req)
    /* use after free and ref underflow */
    p9_req_put(req)

To fix it, we can initialize the refcount to zero before add to idr.

Link: https://lkml.kernel.org/r/20221201033310.18589-1-schspa@gmail.com
Cc: stable@vger.kernel.org # 6.0+ due to 6cda12864c ("9p: Drop kref usage")
Fixes: 728356dede ("9p: Add refcount to p9_req_t")
Reported-by: syzbot+8f1060e2aaf8ca55220b@syzkaller.appspotmail.com
Signed-off-by: Schspa Shi <schspa@gmail.com>
Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-31 13:14:46 +01:00
Dominique Martinet 029a7f1c5d 9p/xen: check logical size for buffer size
[ Upstream commit 391c18cf77 ]

trans_xen did not check the data fits into the buffer before copying
from the xen ring, but we probably should.
Add a check that just skips the request and return an error to
userspace if it did not fit

Tested-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com>
Link: https://lkml.kernel.org/r/20221118135542.63400-1-asmadeus@codewreck.org
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:37:17 +01:00
GUO Zihua 3d1b5fde36 9p/fd: Use P9_HDRSZ for header size
[ Upstream commit 6854fadbee ]

Cleanup hardcoded header sizes to use P9_HDRSZ instead of '7'

Link: https://lkml.kernel.org/r/20221117091159.31533-4-guozihua@huawei.com
Signed-off-by: GUO Zihua <guozihua@huawei.com>
Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com>
[Dominique: commit message adjusted to make sense after offset size
adjustment got removed]
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14 11:37:16 +01:00
Wang Hai 8782b32ef8 net/9p: Fix a potential socket leak in p9_socket_open
[ Upstream commit dcc14cfd7d ]

Both p9_fd_create_tcp() and p9_fd_create_unix() will call
p9_socket_open(). If the creation of p9_trans_fd fails,
p9_fd_create_tcp() and p9_fd_create_unix() will return an
error directly instead of releasing the cscoket, which will
result in a socket leak.

This patch adds sock_release() to fix the leak issue.

Fixes: 6b18662e23 ("9p connect fixes")
Signed-off-by: Wang Hai <wanghai38@huawei.com>
ACKed-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-08 11:28:41 +01:00
Zhengchao Shao ee3ccd1abb 9p/fd: fix issue of list_del corruption in p9_fd_cancel()
[ Upstream commit 11c1095651 ]

Syz reported the following issue:
kernel BUG at lib/list_debug.c:53!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
RIP: 0010:__list_del_entry_valid.cold+0x5c/0x72
Call Trace:
<TASK>
p9_fd_cancel+0xb1/0x270
p9_client_rpc+0x8ea/0xba0
p9_client_create+0x9c0/0xed0
v9fs_session_init+0x1e0/0x1620
v9fs_mount+0xba/0xb80
legacy_get_tree+0x103/0x200
vfs_get_tree+0x89/0x2d0
path_mount+0x4c0/0x1ac0
__x64_sys_mount+0x33b/0x430
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
</TASK>

The process is as follows:
Thread A:                       Thread B:
p9_poll_workfn()                p9_client_create()
...                                 ...
    p9_conn_cancel()                p9_fd_cancel()
        list_del()                      ...
        ...                             list_del()  //list_del
                                                      corruption
There is no lock protection when deleting list in p9_conn_cancel(). After
deleting list in Thread A, thread B will delete the same list again. It
will cause issue of list_del corruption.

Setting req->status to REQ_STATUS_ERROR under lock prevents other
cleanup paths from trying to manipulate req_list.
The other thread can safely check req->status because it still holds a
reference to req at this point.

Link: https://lkml.kernel.org/r/20221110122606.383352-1-shaozhengchao@huawei.com
Fixes: 52f1c45dde ("9p: trans_fd/p9_conn_cancel: drop client lock earlier")
Reported-by: syzbot+9b69b8d10ab4a7d88056@syzkaller.appspotmail.com
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
[Dominique: add description of the fix in commit message]
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-02 17:41:04 +01:00
Dominique Martinet 43bbadb7e4 net/9p: use a dedicated spinlock for trans_fd
commit 296ab4a813 upstream.

Shamelessly copying the explanation from Tetsuo Handa's suggested
patch[1] (slightly reworded):
syzbot is reporting inconsistent lock state in p9_req_put()[2],
for p9_tag_remove() from p9_req_put() from IRQ context is using
spin_lock_irqsave() on "struct p9_client"->lock but trans_fd
(not from IRQ context) is using spin_lock().

Since the locks actually protect different things in client.c and in
trans_fd.c, just replace trans_fd.c's lock by a new one specific to the
transport (client.c's protect the idr for fid/tag allocations,
while trans_fd.c's protects its own req list and request status field
that acts as the transport's state machine)

Link: https://lore.kernel.org/r/20220904112928.1308799-1-asmadeus@codewreck.org
Link: https://lkml.kernel.org/r/2470e028-9b05-2013-7198-1fdad071d999@I-love.SAKURA.ne.jp [1]
Link: https://syzkaller.appspot.com/bug?extid=2f20b523930c32c160cc [2]
Reported-by: syzbot <syzbot+2f20b523930c32c160cc@syzkaller.appspotmail.com>
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-26 09:24:51 +01:00
Tetsuo Handa 0e07032b4b 9p/trans_fd: always use O_NONBLOCK read/write
commit ef575281b2 upstream.

syzbot is reporting hung task at p9_fd_close() [1], for p9_mux_poll_stop()
 from p9_conn_destroy() from p9_fd_close() is failing to interrupt already
started kernel_read() from p9_fd_read() from p9_read_work() and/or
kernel_write() from p9_fd_write() from p9_write_work() requests.

Since p9_socket_open() sets O_NONBLOCK flag, p9_mux_poll_stop() does not
need to interrupt kernel_read()/kernel_write(). However, since p9_fd_open()
does not set O_NONBLOCK flag, but pipe blocks unless signal is pending,
p9_mux_poll_stop() needs to interrupt kernel_read()/kernel_write() when
the file descriptor refers to a pipe. In other words, pipe file descriptor
needs to be handled as if socket file descriptor.

We somehow need to interrupt kernel_read()/kernel_write() on pipes.

A minimal change, which this patch is doing, is to set O_NONBLOCK flag
 from p9_fd_open(), for O_NONBLOCK flag does not affect reading/writing
of regular files. But this approach changes O_NONBLOCK flag on userspace-
supplied file descriptors (which might break userspace programs), and
O_NONBLOCK flag could be changed by userspace. It would be possible to set
O_NONBLOCK flag every time p9_fd_read()/p9_fd_write() is invoked, but still
remains small race window for clearing O_NONBLOCK flag.

If we don't want to manipulate O_NONBLOCK flag, we might be able to
surround kernel_read()/kernel_write() with set_thread_flag(TIF_SIGPENDING)
and recalc_sigpending(). Since p9_read_work()/p9_write_work() works are
processed by kernel threads which process global system_wq workqueue,
signals could not be delivered from remote threads when p9_mux_poll_stop()
 from p9_conn_destroy() from p9_fd_close() is called. Therefore, calling
set_thread_flag(TIF_SIGPENDING)/recalc_sigpending() every time would be
needed if we count on signals for making kernel_read()/kernel_write()
non-blocking.

Link: https://lkml.kernel.org/r/345de429-a88b-7097-d177-adecf9fed342@I-love.SAKURA.ne.jp
Link: https://syzkaller.appspot.com/bug?extid=8b41a1365f1106fd0f33 [1]
Reported-by: syzbot <syzbot+8b41a1365f1106fd0f33@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+8b41a1365f1106fd0f33@syzkaller.appspotmail.com>
Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com>
[Dominique: add comment at Christian's suggestion]
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-26 09:24:51 +01:00
Dominique Martinet a4f1a01b2e 9p: trans_fd/p9_conn_cancel: drop client lock earlier
commit 52f1c45dde upstream.

syzbot reported a double-lock here and we no longer need this
lock after requests have been moved off to local list:
just drop the lock earlier.

Link: https://lkml.kernel.org/r/20220904064028.1305220-1-asmadeus@codewreck.org
Reported-by: syzbot+50f7e8d06c3768dd97f3@syzkaller.appspotmail.com
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Tested-by: Schspa Shi <schspa@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-26 09:24:50 +01:00
Tyler Hicks 7a7188df3e net/9p: Initialize the iounit field during fid creation
[ Upstream commit aa7aeee169 ]

Ensure that the fid's iounit field is set to zero when a new fid is
created. Certain 9P operations, such as OPEN and CREATE, allow the
server to reply with an iounit size which the client code assigns to the
p9_fid struct shortly after the fid is created by p9_fid_create(). On
the other hand, an XATTRWALK operation doesn't allow for the server to
specify an iounit value. The iounit field of the newly allocated p9_fid
struct remained uninitialized in that case. Depending on allocation
patterns, the iounit value could have been something reasonable that was
carried over from previously freed fids or, in the worst case, could
have been arbitrary values from non-fid related usages of the memory
location.

The bug was detected in the Windows Subsystem for Linux 2 (WSL2) kernel
after the uninitialized iounit field resulted in the typical sequence of
two getxattr(2) syscalls, one to get the size of an xattr and another
after allocating a sufficiently sized buffer to fit the xattr value, to
hit an unexpected ERANGE error in the second call to getxattr(2). An
uninitialized iounit field would sometimes force rsize to be smaller
than the xattr value size in p9_client_read_once() and the 9P server in
WSL refused to chunk up the READ on the attr_fid and, instead, returned
ERANGE to the client. The virtfs server in QEMU seems happy to chunk up
the READ and this problem goes undetected there.

Link: https://lkml.kernel.org/r/20220710141402.803295-1-tyhicks@linux.microsoft.com
Fixes: ebf46264a0 ("fs/9p: Add support user. xattr")
Cc: stable@vger.kernel.org
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17 14:24:23 +02:00
Hangyu Hua 8324649b00 net: 9p: fix refcount leak in p9_read_work() error handling
[ Upstream commit 4ac7573e1f ]

p9_req_put need to be called when m->rreq->rc.sdata is NULL to avoid
temporary refcount leak.

Link: https://lkml.kernel.org/r/20220712104438.30800-1-hbh25y@gmail.com
Fixes: 728356dede ("9p: Add refcount to p9_req_t")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
[Dominique: commit wording adjustments, p9_req_put argument fixes for rebase]
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17 14:24:08 +02:00
Kent Overstreet 273c16d93f 9p: Add client parameter to p9_req_put()
[ Upstream commit 8b11ff098a ]

This is to aid in adding mempools, in the next patch.

Link: https://lkml.kernel.org/r/20220704014243.153050-2-kent.overstreet@gmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17 14:24:07 +02:00
Kent Overstreet 3ac76cdab9 9p: Drop kref usage
[ Upstream commit 6cda12864c ]

An upcoming patch is going to require passing the client through
p9_req_put() -> p9_req_free(), but that's awkward with the kref
indirection - so this patch switches to using refcount_t directly.

Link: https://lkml.kernel.org/r/20220704014243.153050-1-kent.overstreet@gmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17 14:24:07 +02:00
Dominique Martinet eb3eed52a7 9p: fix a bunch of checkpatch warnings
[ Upstream commit 6e195b0f7c ]

Sohaib Mohamed started a serie of tiny and incomplete checkpatch fixes but
seemingly stopped halfway -- take over and do most of it.
This is still missing net/9p/trans* and net/9p/protocol.c for a later
time...

Link: http://lkml.kernel.org/r/20211102134608.1588018-3-dominique.martinet@atmark-techno.com
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17 14:24:07 +02:00
Juergen Gross a019d26830 xen/9p: use alloc/free_pages_exact()
Commit 5cadd4bb1d upstream.

Instead of __get_free_pages() and free_pages() use alloc_pages_exact()
and free_pages_exact(). This is in preparation of a change of
gnttab_end_foreign_access() which will prohibit use of high-order
pages.

By using the local variable "order" instead of ring->intf->ring_order
in the error path of xen_9pfs_front_alloc_dataring() another bug is
fixed, as the error path can be entered before ring->intf->ring_order
is being set.

By using alloc_pages_exact() the size in bytes is specified for the
allocation, which fixes another bug for the case of
order < (PAGE_SHIFT - XEN_PAGE_SHIFT).

This is part of CVE-2022-23041 / XSA-396.

Reported-by: Simon Gaiser <simon@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-11 12:22:36 +01:00
Dominique Martinet 6847c42862 9p/net: fix missing error check in p9_check_errors
commit 27eb4c3144 upstream.

Link: https://lkml.kernel.org/r/99338965-d36c-886e-cd0e-1d8fff2b4746@gmail.com
Reported-by: syzbot+06472778c97ed94af66d@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-18 19:17:16 +01:00
Christian Schoenebeck 9c4d94dc9a net/9p: increase default msize to 128k
Let's raise the default msize value to 128k.

The 'msize' option defines the maximum message size allowed for any
message being transmitted (in both directions) between 9p server and 9p
client during a 9p session.

Currently the default 'msize' is just 8k, which is way too conservative.
Such a small 'msize' value has quite a negative performance impact,
because individual 9p messages have to be split up far too often into
numerous smaller messages to fit into this message size limitation.

A default value of just 8k also has a much higher probablity of hitting
short-read issues like: https://gitlab.com/qemu-project/qemu/-/issues/409

Unfortunately user feedback showed that many 9p users are not aware that
this option even exists, nor the negative impact it might have if it is
too low.

Link: http://lkml.kernel.org/r/61ea0f0faaaaf26dd3c762eabe4420306ced21b9.1630770829.git.linux_oss@crudebyte.com
Link: https://lists.gnu.org/archive/html/qemu-devel/2021-03/msg01003.html
Signed-off-by: Christian Schoenebeck <linux_oss@crudebyte.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2021-09-05 08:36:44 +09:00
Christian Schoenebeck 9210fc0a3b net/9p: use macro to define default msize
Use a macro to define the default value for the 'msize' option
at one place instead of using two separate integer literals.

Link: http://lkml.kernel.org/r/28bb651ae0349a7d57e8ddc92c1bd5e62924a912.1630770829.git.linux_oss@crudebyte.com
Signed-off-by: Christian Schoenebeck <linux_oss@crudebyte.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2021-09-05 08:36:44 +09:00
Dominique Martinet 22bb3b7929 net/9p: increase tcp max msize to 1MB
Historically TCP has been limited to 64K buffers, but increasing
msize provides huge performance benefits especially as latency
increase so allow for bigger buffers.

Ideally further improvements could change the allocation from the
current contiguous chunk in slab (kmem_cache) to some scatter-gather
compatible API...

Note this only increases the max possible setting, not the default
value.

Link: http://lkml.kernel.org/r/YTQB5jCbvhmCWzNd@codewreck.org
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2021-09-05 08:35:56 +09:00
Harshvardhan Jha 732b33d0db 9p/xen: Fix end of loop tests for list_for_each_entry
This patch addresses the following problems:
 - priv can never be NULL, so this part of the check is useless
 - if the loop ran through the whole list, priv->client is invalid and
it is more appropriate and sufficient to check for the end of
list_for_each_entry loop condition.

Link: http://lkml.kernel.org/r/20210727000709.225032-1-harshvardhan.jha@oracle.com
Signed-off-by: Harshvardhan Jha <harshvardhan.jha@oracle.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Tested-by: Stefano Stabellini <sstabellini@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2021-07-27 23:01:16 +09:00
Xie Yongji f997ea3b7a 9p/trans_virtio: Remove sysfs file on probe failure
This ensures we don't leak the sysfs file if we failed to
allocate chan->vc_wq during probe.

Link: http://lkml.kernel.org/r/20210517083557.172-1-xieyongji@bytedance.com
Fixes: 86c8437383 ("net/9p: Add sysfs mount_tag file for virtio 9P device")
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2021-07-27 23:01:15 +09:00
Zheng Yongjun 8ab1784df6 9p/trans_virtio: Fix spelling mistakes
reseting  ==> resetting
alloced  ==> allocated
accomodate  ==> accommodate

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-02 14:01:55 -07:00
Xiongfeng Wang 03ff7371cb net: 9p: Correct function names in the kerneldoc comments
Fix the following W=1 kernel build warning(s):

 net/9p/client.c:133: warning: expecting prototype for parse_options(). Prototype was for parse_opts() instead
 net/9p/client.c:269: warning: expecting prototype for p9_req_alloc(). Prototype was for p9_tag_alloc() instead

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-28 17:56:56 -07:00
Xiongfeng Wang 54e625e3bd 9p/trans_fd: Correct function name p9_mux_destroy() in the kerneldoc
Fix the following W=1 kernel build warning(s):

 net/9p/trans_fd.c:881: warning: expecting prototype for p9_mux_destroy(). Prototype was for p9_conn_destroy() instead

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-28 17:56:56 -07:00
Xiongfeng Wang 8bf94a9250 net: 9p: Correct function name errstr2errno() in the kerneldoc comments
Fix the following W=1 kernel build warning(s):

 net/9p/error.c:207: warning: expecting prototype for errstr2errno(). Prototype was for p9_errstr2errno() instead

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-28 17:56:56 -07:00
Jisheng Zhang d65614a01d net: 9p: advance iov on empty read
I met below warning when cating a small size(about 80bytes) txt file
on 9pfs(msize=2097152 is passed to 9p mount option), the reason is we
miss iov_iter_advance() if the read count is 0 for zerocopy case, so
we didn't truncate the pipe, then iov_iter_pipe() thinks the pipe is
full. Fix it by removing the exception for 0 to ensure to call
iov_iter_advance() even on empty read for zerocopy case.

[    8.279568] WARNING: CPU: 0 PID: 39 at lib/iov_iter.c:1203 iov_iter_pipe+0x31/0x40
[    8.280028] Modules linked in:
[    8.280561] CPU: 0 PID: 39 Comm: cat Not tainted 5.11.0+ #6
[    8.281260] RIP: 0010:iov_iter_pipe+0x31/0x40
[    8.281974] Code: 2b 42 54 39 42 5c 76 22 c7 07 20 00 00 00 48 89 57 18 8b 42 50 48 c7 47 08 b
[    8.283169] RSP: 0018:ffff888000cbbd80 EFLAGS: 00000246
[    8.283512] RAX: 0000000000000010 RBX: ffff888000117d00 RCX: 0000000000000000
[    8.283876] RDX: ffff88800031d600 RSI: 0000000000000000 RDI: ffff888000cbbd90
[    8.284244] RBP: ffff888000cbbe38 R08: 0000000000000000 R09: ffff8880008d2058
[    8.284605] R10: 0000000000000002 R11: ffff888000375510 R12: 0000000000000050
[    8.284964] R13: ffff888000cbbe80 R14: 0000000000000050 R15: ffff88800031d600
[    8.285439] FS:  00007f24fd8af600(0000) GS:ffff88803ec00000(0000) knlGS:0000000000000000
[    8.285844] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    8.286150] CR2: 00007f24fd7d7b90 CR3: 0000000000c97000 CR4: 00000000000406b0
[    8.286710] Call Trace:
[    8.288279]  generic_file_splice_read+0x31/0x1a0
[    8.289273]  ? do_splice_to+0x2f/0x90
[    8.289511]  splice_direct_to_actor+0xcc/0x220
[    8.289788]  ? pipe_to_sendpage+0xa0/0xa0
[    8.290052]  do_splice_direct+0x8b/0xd0
[    8.290314]  do_sendfile+0x1ad/0x470
[    8.290576]  do_syscall_64+0x2d/0x40
[    8.290818]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[    8.291409] RIP: 0033:0x7f24fd7dca0a
[    8.292511] Code: c3 0f 1f 80 00 00 00 00 4c 89 d2 4c 89 c6 e9 bd fd ff ff 0f 1f 44 00 00 31 8
[    8.293360] RSP: 002b:00007ffc20932818 EFLAGS: 00000206 ORIG_RAX: 0000000000000028
[    8.293800] RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f24fd7dca0a
[    8.294153] RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000001
[    8.294504] RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
[    8.294867] R10: 0000000001000000 R11: 0000000000000206 R12: 0000000000000003
[    8.295217] R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000000
[    8.295782] ---[ end trace 63317af81b3ca24b ]---

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-03 16:57:59 -08:00
Masahiro Yamada 864e898ba3 net: remove redundant 'depends on NET'
These Kconfig files are included from net/Kconfig, inside the
if NET ... endif.

Remove 'depends on NET', which we know it is already met.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20210125232026.106855-1-masahiroy@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-27 17:04:12 -08:00
Linus Torvalds 70990afa34 9p for 5.11-rc1
- fix long-standing limitation on open-unlink-fop pattern
 - add refcount to p9_fid (fixes the above and will allow for more
 cleanups and simplifications in the future)
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEE/IPbcYBuWt0zoYhOq06b7GqY5nAFAl/gWOYACgkQq06b7GqY
 5nBcHxAArtfxZ4wGa+OMoWt19UvF0bUeYUYdy75rp6awpXmQyMfMZY9oOrZ9L+St
 mS3oLd8Mq7MeJQ+iGKPPOX+085aNhRtxjQOiHlv02fi09zVyNqj1vptq+rTRkKZL
 8KTs+wYSIX2x1WensDBdohYFiWf87vCWyywpQ/1Vm0585mI8B88N3/H5EpkLbPZn
 1bgXkakgd2hS+rKu6vJGV8lCJ8eKOSpQ3WUK0WQhY6ysJEL9dbl00qyNQ4kq2UgI
 i3CpWC/86297KJOehPmegpVwqTIL5wrCkhQy7sNxDkR9E4Q3VoKTNSrnRDtBI0x/
 mRCEnc/2Pf76Zv3LpGXnLFSnDLTQaO842Hla92RZJCcHaDtGDwV9Znq6sZgn+pdV
 wlEpT383s+7AC/X1EFvLPMr5PHrEM1KW25YEYQI78X2hh8G+utW5p3+vu70b0PyT
 Z7P9yBW4aU4cZb3XcZZihatZG2P1LxHyjNMmn4YBdUeQuitdiJGc2KwjVyKXi9PX
 +t6xxI+YAIhu/5I9fRtOoIDQNTjsRRE+4FzRKd2kvxW5Z5sV/bZCf6CHnQ2uKYVP
 fEMYd0GhjrUABbJPLLdFlBXaV+yigvwKtABDnJ5KSA9NlDSVBGewTRa2I+9DoclL
 yQS4hELuvQsUNCo4AkICixo9vABt0j1OhXlo+B0WVk8Ilh9Wxpc=
 =DKlc
 -----END PGP SIGNATURE-----

Merge tag '9p-for-5.11-rc1' of git://github.com/martinetd/linux

Pull 9p update from Dominique Martinet:

 - fix long-standing limitation on open-unlink-fop pattern

 - add refcount to p9_fid (fixes the above and will allow for more
   cleanups and simplifications in the future)

* tag '9p-for-5.11-rc1' of git://github.com/martinetd/linux:
  9p: Remove unnecessary IS_ERR() check
  9p: Uninitialized variable in v9fs_writeback_fid()
  9p: Fix writeback fid incorrectly being attached to dentry
  9p: apply review requests for fid refcounting
  9p: add refcount to p9_fid struct
  fs/9p: search open fids first
  fs/9p: track open fids
  fs/9p: fix create-unlink-getattr idiom
2020-12-21 10:28:02 -08:00
Dominique Martinet ff5e72ebef 9p: apply review requests for fid refcounting
Fix style issues in parent commit ("apply review requests for fid
refcounting"), no functional change.

Link: http://lkml.kernel.org/r/1605802012-31133-2-git-send-email-asmadeus@codewreck.org
Fixes: 6636b6dcc3 ("9p: add refcount to p9_fid struct")
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2020-11-19 17:21:34 +01:00
Jianyong Wu 6636b6dcc3 9p: add refcount to p9_fid struct
Fix race issue in fid contention.

Eric's and Greg's patch offer a mechanism to fix open-unlink-f*syscall
bug in 9p. But there is race issue in fid parallel accesses.
As Greg's patch stores all of fids from opened files into according inode,
so all the lookup fid ops can retrieve fid from inode preferentially. But
there is no mechanism to handle the fid contention issue. For example,
there are two threads get the same fid in the same time and one of them
clunk the fid before the other thread ready to discard the fid. In this
scenario, it will lead to some fatal problems, even kernel core dump.

I introduce a mechanism to fix this race issue. A counter field introduced
into p9_fid struct to store the reference counter to the fid. When a fid
is allocated from the inode or dentry, the counter will increase, and
will decrease at the end of its occupation. It is guaranteed that the
fid won't be clunked before the reference counter go down to 0, then
we can avoid the clunked fid to be used.

tests:
race issue test from the old test case:
for file in {01..50}; do touch f.${file}; done
seq 1 1000 | xargs -n 1 -P 50 -I{} cat f.* > /dev/null

open-unlink-f*syscall test:
I have tested for f*syscall include: ftruncate fstat fchown fchmod faccessat.

Link: http://lkml.kernel.org/r/20200923141146.90046-5-jianyong.wu@arm.com
Fixes: 478ba09edc ("fs/9p: search open fids first")
Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2020-11-19 17:20:39 +01:00
Eric Van Hensbergen 154372e67d fs/9p: fix create-unlink-getattr idiom
Fixes several outstanding bug reports of not being able to getattr from an
open file after an unlink.  This patch cleans up transient fids on an unlink
and will search open fids on a client if it detects a dentry that appears to
have been unlinked.  This search is necessary because fstat does not pass fd
information through the VFS API to the filesystem, only the dentry which for
9p has an imperfect match to fids.

Inherent in this patch is also a fix for the qid handling on create/open
which apparently wasn't being set correctly and was necessary for the search
to succeed.

A possible optimization over this fix is to include accounting of open fids
with the inode in the private data (in a similar fashion to the way we track
transient fids with dentries).  This would allow a much quicker search for
a matching open fid.

(changed v9fs_fid_find_global to v9fs_fid_find_inode in comment)

Link: http://lkml.kernel.org/r/20200923141146.90046-2-jianyong.wu@arm.com
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2020-11-03 09:29:31 +01:00
Andrew Lunn 760b3d61fb net: 9p: Fix kerneldoc warnings of missing parameters etc
net/9p/client.c:420: warning: Function parameter or member 'c' not described in 'p9_client_cb'
net/9p/client.c:420: warning: Function parameter or member 'req' not described in 'p9_client_cb'
net/9p/client.c:420: warning: Function parameter or member 'status' not described in 'p9_client_cb'
net/9p/client.c:568: warning: Function parameter or member 'uidata' not described in 'p9_check_zc_errors'
net/9p/trans_common.c:23: warning: Function parameter or member 'nr_pages' not described in 'p9_release_pages'
net/9p/trans_common.c:23: warning: Function parameter or member 'pages' not described in 'p9_release_pages'
net/9p/trans_fd.c:132: warning: Function parameter or member 'rreq' not described in 'p9_conn'
net/9p/trans_fd.c:132: warning: Function parameter or member 'wreq' not described in 'p9_conn'
net/9p/trans_fd.c:56: warning: Function parameter or member 'privport' not described in 'p9_fd_opts'
net/9p/trans_rdma.c:113: warning: Function parameter or member 'cqe' not described in 'p9_rdma_context'
net/9p/trans_rdma.c:129: warning: Function parameter or member 'privport' not described in 'p9_rdma_opts'
net/9p/trans_virtio.c:215: warning: Function parameter or member 'limit' not described in 'pack_sg_list_p'
net/9p/trans_virtio.c:83: warning: Function parameter or member 'chan_list' not described in 'virtio_chan'
net/9p/trans_virtio.c:83: warning: Function parameter or member 'p9_max_pages' not described in 'virtio_chan'
net/9p/trans_virtio.c:83: warning: Function parameter or member 'ring_bufs_avail' not described in 'virtio_chan'
net/9p/trans_virtio.c:83: warning: Function parameter or member 'tag' not described in 'virtio_chan'
net/9p/trans_virtio.c:83: warning: Function parameter or member 'vc_wq' not described in 'virtio_chan'

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Dominique Martinet <asmadeus@codewreck.org>
Link: https://lore.kernel.org/r/20201031182655.1082065-1-andrew@lunn.ch
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-02 12:25:52 -08:00
Anant Thazhemadam 7ca1db21ef net: 9p: initialize sun_server.sun_path to have addr's value only when addr is valid
In p9_fd_create_unix, checking is performed to see if the addr (passed
as an argument) is NULL or not.
However, no check is performed to see if addr is a valid address, i.e.,
it doesn't entirely consist of only 0's.
The initialization of sun_server.sun_path to be equal to this faulty
addr value leads to an uninitialized variable, as detected by KMSAN.
Checking for this (faulty addr) and returning a negative error number
appropriately, resolves this issue.

Link: http://lkml.kernel.org/r/20201012042404.2508-1-anant.thazhemadam@gmail.com
Reported-by: syzbot+75d51fe5bf4ebe988518@syzkaller.appspotmail.com
Tested-by: syzbot+75d51fe5bf4ebe988518@syzkaller.appspotmail.com
Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2020-10-12 10:05:47 +02:00
Ye Bin 316a1bef0d 9p/xen: Fix format argument warning
Fix follow warnings:
[net/9p/trans_xen.c:454]: (warning) %u in format string (no. 1) requires
'unsigned int' but the argument type is 'int'.
[net/9p/trans_xen.c:460]: (warning) %u in format string (no. 1) requires
'unsigned int' but the argument type is 'int'.

Link: http://lkml.kernel.org/r/20201009080552.89918-1-yebin10@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2020-10-09 10:23:29 +02:00
Gustavo A. R. Silva df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
Linus Torvalds 410520d07f 9p pull request for inclusion in 5.9
- some code cleanup
 - a couple of static analysis fixes
 - setattr: try to pick a fid associated with the file rather than the
 dentry, which might sometimes matter
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEE/IPbcYBuWt0zoYhOq06b7GqY5nAFAl83dvkACgkQq06b7GqY
 5nDk4g/+KNpbIFHhDyhCzmZ1WbaUYlZseFm8VBR9dzwOkXCuVl+WQd9ducYlEifT
 cZ29xmEuom01LhFOs6VzC+IODQq3h1WvEbVRfCSlLEWvfHyPODSDY8mrn+1TdOZL
 UOOP1wUjaDqmAcBQ4PSDNmj2cONNWPqkgnuyswjsBpabOY/U8FxG9J/QiPfC12zs
 QoF5800OiuLYS5SefI9kKJ47DkTLpm/aq7/Z1liAxJBzHrguORjg16cssXhWeysD
 jEMD3pIrsqMDX/vNkAO0DaR8FWvxTFZR1Bza1ylJiUy3K3rLXKfo+42jiCnuo5e9
 uhA012RfiCZB3kIsLe5hCPXUWz0MhizaJAPkceHsgUtkuiU2qXyY05HEvS2HHl0s
 inqR8gRkZ2NhROx1R/0q+Wu2posCBderDwg7Mkzt/7j5Ue3cTIKvbeBxH9iLLaK+
 rHp0NbfP6wYN5qKjH1rru1IOmaUCV2HHV6x/alnwaVBfZqg5HYKkzlS7M+5hAbtb
 niLFXXCtPBGqS+u9w7sruj6utuiJjXBfB1ejaawY+frS41+v3NkHjjUWCH67u8I9
 u3pmPpvm5o7gRoRmvmxEdSb+jAYZwLTcbkUhRMHLQOHCBZXtcul41p2BUpoBm0zw
 42mlMMMBAjaxtzLlryvACg5lx6x7ykE4pExKAc0dzrzWfgzwEZQ=
 =hwGq
 -----END PGP SIGNATURE-----

Merge tag '9p-for-5.9-rc1' of git://github.com/martinetd/linux

Pull 9p updates from Dominique Martinet:

 - some code cleanup

 - a couple of static analysis fixes

 - setattr: try to pick a fid associated with the file rather than the
   dentry, which might sometimes matter

* tag '9p-for-5.9-rc1' of git://github.com/martinetd/linux:
  9p: Remove unneeded cast from memory allocation
  9p: remove unused code in 9p
  net/9p: Fix sparse endian warning in trans_fd.c
  9p: Fix memory leak in v9fs_mount
  9p: retrieve fid from file when file instance exist.
2020-08-15 08:34:36 -07:00
David S. Miller bd0b33b248 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Resolved kernel/bpf/btf.c using instructions from merge commit
69138b34a7

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-02 01:02:12 -07:00
Wang Hai 74d6a5d566 9p/trans_fd: Fix concurrency del of req_list in p9_fd_cancelled/p9_read_work
p9_read_work and p9_fd_cancelled may be called concurrently.
In some cases, req->req_list may be deleted by both p9_read_work
and p9_fd_cancelled.

We can fix it by ignoring replies associated with a cancelled
request and ignoring cancelled request if message has been received
before lock.

Link: http://lkml.kernel.org/r/20200612090833.36149-1-wanghai38@huawei.com
Fixes: 60ff779c4a ("9p: client: remove unused code and any reference to "cancelled" function")
Cc: <stable@vger.kernel.org> # v3.12+
Reported-by: syzbot+77a25acfa0382e06ab23@syzkaller.appspotmail.com
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2020-07-19 14:58:47 +02:00
Alexander Kapshuk 6db6ea79c5 net/9p: Fix sparse endian warning in trans_fd.c
Address sparse endian warning:
net/9p/trans_fd.c:932:28: warning: incorrect type in assignment (different base types)
net/9p/trans_fd.c:932:28:    expected restricted __be32 [addressable] [assigned] [usertype] s_addr
net/9p/trans_fd.c:932:28:    got unsigned long

Link: http://lkml.kernel.org/r/20200618183417.5423-1-alexander.kapshuk@gmail.com
Signed-off-by: Alexander Kapshuk <alexander.kapshuk@gmail.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2020-07-19 14:58:47 +02:00
Christoph Hellwig a39c46067c net/9p: validate fds in p9_fd_open
p9_fd_open just fgets file descriptors passed in from userspace, but
doesn't verify that they are valid for read or writing.  This gets
cought down in the VFS when actually attempting a read or write, but
a new warning added in linux-next upsets syzcaller.

Fix this by just verifying the fds early on.

Link: http://lkml.kernel.org/r/20200710085722.435850-1-hch@lst.de
Reported-by: syzbot+e6f77e16ff68b2434a2c@syzkaller.appspotmail.com
Signed-off-by: Christoph Hellwig <hch@lst.de>
[Dominique: amend goto as per Doug Nazar's review]
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2020-07-19 14:58:29 +02:00