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authorBaokun Li2024-02-17 16:14:31 +0800
committerChristian Brauner2024-02-20 09:46:07 +0100
commite21a2f17566cbd64926fb8f16323972f7a064444 (patch)
treee7ae68dc4c4f667d66486464255d0c8eceeded53
parentca9ca1a5d5a980550db1001ea825f9fdfa550b83 (diff)
cachefiles: fix memory leak in cachefiles_add_cache()
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: 9ae326a69004 ("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>
-rw-r--r--fs/cachefiles/cache.c2
-rw-r--r--fs/cachefiles/daemon.c1
2 files changed, 3 insertions, 0 deletions
diff --git a/fs/cachefiles/cache.c b/fs/cachefiles/cache.c
index 7077f72e6f47..f449f7340aad 100644
--- a/fs/cachefiles/cache.c
+++ b/fs/cachefiles/cache.c
@@ -168,6 +168,8 @@ error_unsupported:
dput(root);
error_open_root:
cachefiles_end_secure(cache, saved_cred);
+ put_cred(cache->cache_cred);
+ cache->cache_cred = NULL;
error_getsec:
fscache_relinquish_cache(cache_cookie);
cache->cache = NULL;
diff --git a/fs/cachefiles/daemon.c b/fs/cachefiles/daemon.c
index 3f24905f4066..6465e2574230 100644
--- a/fs/cachefiles/daemon.c
+++ b/fs/cachefiles/daemon.c
@@ -816,6 +816,7 @@ static void cachefiles_daemon_unbind(struct cachefiles_cache *cache)
cachefiles_put_directory(cache->graveyard);
cachefiles_put_directory(cache->store);
mntput(cache->mnt);
+ put_cred(cache->cache_cred);
kfree(cache->rootdirname);
kfree(cache->secctx);