724b6bab0d
While working on processing dlm message in softirq context I experienced
the following KASAN use-after-free warning:
[ 151.760477] ==================================================================
[ 151.761803] BUG: KASAN: use-after-free in dlm_midcomms_commit_mhandle+0x19d/0x4b0
[ 151.763414] Read of size 4 at addr ffff88811a980c60 by task lock_torture/1347
[ 151.765284] CPU: 7 PID: 1347 Comm: lock_torture Not tainted 6.1.0-rc4+ #2828
[ 151.766778] Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.16.0-3.module+el8.7.0+16134+e5908aa2 04/01/2014
[ 151.768726] Call Trace:
[ 151.769277] <TASK>
[ 151.769748] dump_stack_lvl+0x5b/0x86
[ 151.770556] print_report+0x180/0x4c8
[ 151.771378] ? kasan_complete_mode_report_info+0x7c/0x1e0
[ 151.772241] ? dlm_midcomms_commit_mhandle+0x19d/0x4b0
[ 151.773069] kasan_report+0x93/0x1a0
[ 151.773668] ? dlm_midcomms_commit_mhandle+0x19d/0x4b0
[ 151.774514] __asan_load4+0x7e/0xa0
[ 151.775089] dlm_midcomms_commit_mhandle+0x19d/0x4b0
[ 151.775890] ? create_message.isra.29.constprop.64+0x57/0xc0
[ 151.776770] send_common+0x19f/0x1b0
[ 151.777342] ? remove_from_waiters+0x60/0x60
[ 151.778017] ? lock_downgrade+0x410/0x410
[ 151.778648] ? __this_cpu_preempt_check+0x13/0x20
[ 151.779421] ? rcu_lockdep_current_cpu_online+0x88/0xc0
[ 151.780292] _convert_lock+0x46/0x150
[ 151.780893] convert_lock+0x7b/0xc0
[ 151.781459] dlm_lock+0x3ac/0x580
[ 151.781993] ? 0xffffffffc0540000
[ 151.782522] ? torture_stop+0x120/0x120 [dlm_locktorture]
[ 151.783379] ? dlm_scan_rsbs+0xa70/0xa70
[ 151.784003] ? preempt_count_sub+0xd6/0x130
[ 151.784661] ? is_module_address+0x47/0x70
[ 151.785309] ? torture_stop+0x120/0x120 [dlm_locktorture]
[ 151.786166] ? 0xffffffffc0540000
[ 151.786693] ? lockdep_init_map_type+0xc3/0x360
[ 151.787414] ? 0xffffffffc0540000
[ 151.787947] torture_dlm_lock_sync.isra.3+0xe9/0x150 [dlm_locktorture]
[ 151.789004] ? torture_stop+0x120/0x120 [dlm_locktorture]
[ 151.789858] ? 0xffffffffc0540000
[ 151.790392] ? lock_torture_cleanup+0x20/0x20 [dlm_locktorture]
[ 151.791347] ? delay_tsc+0x94/0xc0
[ 151.791898] torture_ex_iter+0xc3/0xea [dlm_locktorture]
[ 151.792735] ? torture_start+0x30/0x30 [dlm_locktorture]
[ 151.793606] lock_torture+0x177/0x270 [dlm_locktorture]
[ 151.794448] ? torture_dlm_lock_sync.isra.3+0x150/0x150 [dlm_locktorture]
[ 151.795539] ? lock_torture_stats+0x80/0x80 [dlm_locktorture]
[ 151.796476] ? do_raw_spin_lock+0x11e/0x1e0
[ 151.797152] ? mark_held_locks+0x34/0xb0
[ 151.797784] ? _raw_spin_unlock_irqrestore+0x30/0x70
[ 151.798581] ? __kthread_parkme+0x79/0x110
[ 151.799246] ? trace_preempt_on+0x2a/0xf0
[ 151.799902] ? __kthread_parkme+0x79/0x110
[ 151.800579] ? preempt_count_sub+0xd6/0x130
[ 151.801271] ? __kasan_check_read+0x11/0x20
[ 151.801963] ? __kthread_parkme+0xec/0x110
[ 151.802630] ? lock_torture_stats+0x80/0x80 [dlm_locktorture]
[ 151.803569] kthread+0x192/0x1d0
[ 151.804104] ? kthread_complete_and_exit+0x30/0x30
[ 151.804881] ret_from_fork+0x1f/0x30
[ 151.805480] </TASK>
[ 151.806111] Allocated by task 1347:
[ 151.806681] kasan_save_stack+0x26/0x50
[ 151.807308] kasan_set_track+0x25/0x30
[ 151.807920] kasan_save_alloc_info+0x1e/0x30
[ 151.808609] __kasan_slab_alloc+0x63/0x80
[ 151.809263] kmem_cache_alloc+0x1ad/0x830
[ 151.809916] dlm_allocate_mhandle+0x17/0x20
[ 151.810590] dlm_midcomms_get_mhandle+0x96/0x260
[ 151.811344] _create_message+0x95/0x180
[ 151.811994] create_message.isra.29.constprop.64+0x57/0xc0
[ 151.812880] send_common+0x129/0x1b0
[ 151.813467] _convert_lock+0x46/0x150
[ 151.814074] convert_lock+0x7b/0xc0
[ 151.814648] dlm_lock+0x3ac/0x580
[ 151.815199] torture_dlm_lock_sync.isra.3+0xe9/0x150 [dlm_locktorture]
[ 151.816258] torture_ex_iter+0xc3/0xea [dlm_locktorture]
[ 151.817129] lock_torture+0x177/0x270 [dlm_locktorture]
[ 151.817986] kthread+0x192/0x1d0
[ 151.818518] ret_from_fork+0x1f/0x30
[ 151.819369] Freed by task 1336:
[ 151.819890] kasan_save_stack+0x26/0x50
[ 151.820514] kasan_set_track+0x25/0x30
[ 151.821128] kasan_save_free_info+0x2e/0x50
[ 151.821812] __kasan_slab_free+0x107/0x1a0
[ 151.822483] kmem_cache_free+0x204/0x5e0
[ 151.823152] dlm_free_mhandle+0x18/0x20
[ 151.823781] dlm_mhandle_release+0x2e/0x40
[ 151.824454] rcu_core+0x583/0x1330
[ 151.825047] rcu_core_si+0xe/0x20
[ 151.825594] __do_softirq+0xf4/0x5c2
[ 151.826450] Last potentially related work creation:
[ 151.827238] kasan_save_stack+0x26/0x50
[ 151.827870] __kasan_record_aux_stack+0xa2/0xc0
[ 151.828609] kasan_record_aux_stack_noalloc+0xb/0x20
[ 151.829415] call_rcu+0x4c/0x760
[ 151.829954] dlm_mhandle_delete+0x97/0xb0
[ 151.830718] dlm_process_incoming_buffer+0x2fc/0xb30
[ 151.831524] process_dlm_messages+0x16e/0x470
[ 151.832245] process_one_work+0x505/0xa10
[ 151.832905] worker_thread+0x67/0x650
[ 151.833507] kthread+0x192/0x1d0
[ 151.834046] ret_from_fork+0x1f/0x30
[ 151.834900] The buggy address belongs to the object at ffff88811a980c30
which belongs to the cache dlm_mhandle of size 88
[ 151.836894] The buggy address is located 48 bytes inside of
88-byte region [ffff88811a980c30, ffff88811a980c88)
[ 151.839007] The buggy address belongs to the physical page:
[ 151.839904] page:0000000076cf5d62 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11a980
[ 151.841378] flags: 0x8000000000000200(slab|zone=2)
[ 151.842141] raw: 8000000000000200 0000000000000000 dead000000000122 ffff8881089b43c0
[ 151.843401] raw: 0000000000000000 0000000000220022 00000001ffffffff 0000000000000000
[ 151.844640] page dumped because: kasan: bad access detected
[ 151.845822] Memory state around the buggy address:
[ 151.846602] ffff88811a980b00: fb fb fb fb fc fc fc fc fa fb fb fb fb fb fb fb
[ 151.847761] ffff88811a980b80: fb fb fb fc fc fc fc fa fb fb fb fb fb fb fb fb
[ 151.848921] >ffff88811a980c00: fb fb fc fc fc fc fa fb fb fb fb fb fb fb fb fb
[ 151.850076] ^
[ 151.851085] ffff88811a980c80: fb fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb
[ 151.852269] ffff88811a980d00: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb fc
[ 151.853428] ==================================================================
[ 151.855618] Disabling lock debugging due to kernel taint
It is accessing a mhandle in dlm_midcomms_commit_mhandle() and the mhandle
was freed by a call_rcu() call in dlm_process_incoming_buffer(),
dlm_mhandle_delete(). It looks like it was freed because an ack of
this message was received. There is a short race between committing the
dlm message to be transmitted and getting an ack back. If the ack is
faster than returning from dlm_midcomms_commit_msg_3_2(), then we run
into a use-after free because we still need to reference the mhandle when
calling srcu_read_unlock().
To avoid that, we don't allow that mhandle to be freed between
dlm_midcomms_commit_msg_3_2() and srcu_read_unlock() by using rcu read
lock. We can do that because mhandle is protected by rcu handling.
Cc: stable@vger.kernel.org
Fixes:
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|---|---|---|
| .. | ||
| 9p | ||
| adfs | ||
| affs | ||
| afs | ||
| autofs | ||
| befs | ||
| bfs | ||
| btrfs | ||
| cachefiles | ||
| ceph | ||
| cifs | ||
| coda | ||
| configfs | ||
| cramfs | ||
| crypto | ||
| debugfs | ||
| devpts | ||
| dlm | ||
| ecryptfs | ||
| efivarfs | ||
| efs | ||
| erofs | ||
| exfat | ||
| exportfs | ||
| ext2 | ||
| ext4 | ||
| f2fs | ||
| fat | ||
| freevxfs | ||
| fscache | ||
| fuse | ||
| gfs2 | ||
| hfs | ||
| hfsplus | ||
| hostfs | ||
| hpfs | ||
| hugetlbfs | ||
| iomap | ||
| isofs | ||
| jbd2 | ||
| jffs2 | ||
| jfs | ||
| kernfs | ||
| ksmbd | ||
| lockd | ||
| minix | ||
| netfs | ||
| nfs | ||
| nfs_common | ||
| nfsd | ||
| nilfs2 | ||
| nls | ||
| notify | ||
| ntfs | ||
| ntfs3 | ||
| ocfs2 | ||
| omfs | ||
| openpromfs | ||
| orangefs | ||
| overlayfs | ||
| proc | ||
| pstore | ||
| qnx4 | ||
| qnx6 | ||
| quota | ||
| ramfs | ||
| reiserfs | ||
| romfs | ||
| smbfs_common | ||
| squashfs | ||
| sysfs | ||
| sysv | ||
| tracefs | ||
| ubifs | ||
| udf | ||
| ufs | ||
| unicode | ||
| vboxsf | ||
| verity | ||
| xfs | ||
| zonefs | ||
| Kconfig | ||
| Kconfig.binfmt | ||
| Makefile | ||
| aio.c | ||
| anon_inodes.c | ||
| attr.c | ||
| bad_inode.c | ||
| binfmt_elf.c | ||
| binfmt_elf_fdpic.c | ||
| binfmt_elf_test.c | ||
| binfmt_flat.c | ||
| binfmt_misc.c | ||
| binfmt_script.c | ||
| buffer.c | ||
| char_dev.c | ||
| compat_binfmt_elf.c | ||
| coredump.c | ||
| d_path.c | ||
| dax.c | ||
| dcache.c | ||
| direct-io.c | ||
| drop_caches.c | ||
| eventfd.c | ||
| eventpoll.c | ||
| exec.c | ||
| fcntl.c | ||
| fhandle.c | ||
| file.c | ||
| file_table.c | ||
| filesystems.c | ||
| fs-writeback.c | ||
| fs_context.c | ||
| fs_parser.c | ||
| fs_pin.c | ||
| fs_struct.c | ||
| fs_types.c | ||
| fsopen.c | ||
| init.c | ||
| inode.c | ||
| internal.h | ||
| ioctl.c | ||
| kernel_read_file.c | ||
| libfs.c | ||
| locks.c | ||
| mbcache.c | ||
| mount.h | ||
| mpage.c | ||
| namei.c | ||
| namespace.c | ||
| no-block.c | ||
| nsfs.c | ||
| open.c | ||
| pipe.c | ||
| pnode.c | ||
| pnode.h | ||
| posix_acl.c | ||
| proc_namespace.c | ||
| read_write.c | ||
| readdir.c | ||
| remap_range.c | ||
| select.c | ||
| seq_file.c | ||
| signalfd.c | ||
| splice.c | ||
| stack.c | ||
| stat.c | ||
| statfs.c | ||
| super.c | ||
| sync.c | ||
| sysctls.c | ||
| timerfd.c | ||
| userfaultfd.c | ||
| utimes.c | ||
| xattr.c | ||