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authorDavid Howells <dhowells@redhat.com>2024-01-19 23:49:34 +0300
committerDavid Howells <dhowells@redhat.com>2024-01-23 01:25:15 +0300
commitc3d6569a43322f371e7ba0ad386112723757ac8f (patch)
treea5e95c94000f9ddd3c19dc9fd8db9214e095022f /fs/cachefiles
parent843609df0be792991b3c4a720d6be4828d48dec4 (diff)
downloadlinux-c3d6569a43322f371e7ba0ad386112723757ac8f.tar.xz
cachefiles, erofs: Fix NULL deref in when cachefiles is not doing ondemand-mode
cachefiles_ondemand_init_object() as called from cachefiles_open_file() and cachefiles_create_tmpfile() does not check if object->ondemand is set before dereferencing it, leading to an oops something like: RIP: 0010:cachefiles_ondemand_init_object+0x9/0x41 ... Call Trace: <TASK> cachefiles_open_file+0xc9/0x187 cachefiles_lookup_cookie+0x122/0x2be fscache_cookie_state_machine+0xbe/0x32b fscache_cookie_worker+0x1f/0x2d process_one_work+0x136/0x208 process_scheduled_works+0x3a/0x41 worker_thread+0x1a2/0x1f6 kthread+0xca/0xd2 ret_from_fork+0x21/0x33 Fix this by making cachefiles_ondemand_init_object() return immediately if cachefiles->ondemand is NULL. Fixes: 3c5ecfe16e76 ("cachefiles: extract ondemand info field from cachefiles_object") Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Gao Xiang <xiang@kernel.org> cc: Chao Yu <chao@kernel.org> cc: Yue Hu <huyue2@coolpad.com> cc: Jeffle Xu <jefflexu@linux.alibaba.com> cc: linux-erofs@lists.ozlabs.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org
Diffstat (limited to 'fs/cachefiles')
-rw-r--r--fs/cachefiles/ondemand.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c
index 5fd74ec60bef..4ba42f1fa3b4 100644
--- a/fs/cachefiles/ondemand.c
+++ b/fs/cachefiles/ondemand.c
@@ -539,6 +539,9 @@ int cachefiles_ondemand_init_object(struct cachefiles_object *object)
struct fscache_volume *volume = object->volume->vcookie;
size_t volume_key_size, cookie_key_size, data_len;
+ if (!object->ondemand)
+ return 0;
+
/*
* CacheFiles will firstly check the cache file under the root cache
* directory. If the coherency check failed, it will fallback to