On 2/17/24 4:14 PM, Baokun Li wrote: > 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@xxxxxxxxxxxxxxx > Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx> LGTM. Reviewed-by: Jingbo Xu <jefflexu@xxxxxxxxxxxxxxxxx> > --- > fs/cachefiles/cache.c | 2 ++ > fs/cachefiles/daemon.c | 1 + > 2 files changed, 3 insertions(+) > > 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 @@ int cachefiles_add_cache(struct cachefiles_cache *cache) > 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); -- Thanks, Jingbo -- You received this message because you are subscribed to the Google Groups "linux-cachefs@xxxxxxxxxx" group. To unsubscribe from this group and stop receiving emails from it, send an email to linux-cachefs+unsubscribe@xxxxxxxxxx.