70e329b440
commit cda4672da1c26835dcbd7aec2bfed954eda9b5ef upstream. In fs/ceph/caps.c, in encode_cap_msg(), "use after free" error was caught by KASAN at this line - 'ceph_buffer_get(arg->xattr_buf);'. This implies before the refcount could be increment here, it was freed. In same file, in "handle_cap_grant()" refcount is decremented by this line - 'ceph_buffer_put(ci->i_xattrs.blob);'. It appears that a race occurred and resource was freed by the latter line before the former line could increment it. encode_cap_msg() is called by __send_cap() and __send_cap() is called by ceph_check_caps() after calling __prep_cap(). __prep_cap() is where arg->xattr_buf is assigned to ci->i_xattrs.blob. This is the spot where the refcount must be increased to prevent "use after free" error. Cc: stable@vger.kernel.org Link: https://tracker.ceph.com/issues/59259 Signed-off-by: Rishabh Dave <ridave@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Xiubo Li <xiubli@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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| .. | ||
| Kconfig | ||
| Makefile | ||
| acl.c | ||
| addr.c | ||
| cache.c | ||
| cache.h | ||
| caps.c | ||
| ceph_frag.c | ||
| debugfs.c | ||
| dir.c | ||
| export.c | ||
| file.c | ||
| inode.c | ||
| io.c | ||
| io.h | ||
| ioctl.c | ||
| ioctl.h | ||
| locks.c | ||
| mds_client.c | ||
| mds_client.h | ||
| mdsmap.c | ||
| metric.c | ||
| metric.h | ||
| quota.c | ||
| snap.c | ||
| strings.c | ||
| super.c | ||
| super.h | ||
| util.c | ||
| xattr.c | ||