linux/fs/cachefiles
Baokun Li 8b218e2f0a cachefiles: fix memory leak in cachefiles_add_cache()
commit e21a2f1756 upstream.

The following memory leak was reported after unbinding /dev/cachefiles:

==================================================================
unreferenced object 0xffff9b674176e3c0 (size 192):
  comm "cachefilesd2", pid 680, jiffies 4294881224
  hex dump (first 32 bytes):
    01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace (crc ea38a44b):
    [<ffffffff8eb8a1a5>] kmem_cache_alloc+0x2d5/0x370
    [<ffffffff8e917f86>] prepare_creds+0x26/0x2e0
    [<ffffffffc002eeef>] cachefiles_determine_cache_security+0x1f/0x120
    [<ffffffffc00243ec>] cachefiles_add_cache+0x13c/0x3a0
    [<ffffffffc0025216>] cachefiles_daemon_write+0x146/0x1c0
    [<ffffffff8ebc4a3b>] vfs_write+0xcb/0x520
    [<ffffffff8ebc5069>] ksys_write+0x69/0xf0
    [<ffffffff8f6d4662>] do_syscall_64+0x72/0x140
    [<ffffffff8f8000aa>] entry_SYSCALL_64_after_hwframe+0x6e/0x76
==================================================================

Put the reference count of cache_cred in cachefiles_daemon_unbind() to
fix the problem. And also put cache_cred in cachefiles_add_cache() error
branch to avoid memory leaks.

Fixes: 9ae326a690 ("CacheFiles: A cache that backs onto a mounted filesystem")
CC: stable@vger.kernel.org
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Link: https://lore.kernel.org/r/20240217081431.796809-1-libaokun1@huawei.com
Acked-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-01 13:26:32 +01:00
..
cache.c cachefiles: fix memory leak in cachefiles_add_cache() 2024-03-01 13:26:32 +01:00
daemon.c cachefiles: fix memory leak in cachefiles_add_cache() 2024-03-01 13:26:32 +01:00
error_inject.c cachefiles: Add some error injection support 2022-01-07 13:40:56 +00:00
interface.c cachefiles: notify the user daemon when withdrawing cookie 2022-05-18 00:11:17 +08:00
internal.h cachefiles: make on-demand request distribution fairer 2022-08-31 16:41:10 +01:00
io.c cachefiles: implement on-demand read 2022-05-18 00:11:18 +08:00
Kconfig cachefiles: notify the user daemon when looking up cookie 2022-05-18 00:11:17 +08:00
key.c cachefiles: Implement key to filename encoding 2022-01-07 13:42:16 +00:00
main.c cachefiles: Implement object lifecycle funcs 2022-01-07 13:42:08 +00:00
Makefile cachefiles: notify the user daemon when looking up cookie 2022-05-18 00:11:17 +08:00
namei.c mm, netfs, fscache: stop read optimisation when folio removed from pagecache 2024-01-10 17:10:31 +01:00
ondemand.c cachefiles: make on-demand request distribution fairer 2022-08-31 16:41:10 +01:00
security.c cachefiles: Add security derivation 2022-01-07 13:41:14 +00:00
volume.c fscache, cachefiles: Store the volume coherency data 2022-01-07 13:43:03 +00:00
xattr.c cachefiles: Fix KASAN slab-out-of-bounds in cachefiles_set_volume_xattr 2022-04-08 23:32:40 +01:00