summaryrefslogtreecommitdiff
path: root/fs/f2fs
diff options
context:
space:
mode:
authorChao Yu <chao@kernel.org>2021-12-06 22:44:19 +0800
committerJaegeuk Kim <jaegeuk@kernel.org>2021-12-10 15:48:32 -0800
commit9056d6489f5a41cfbb67f719d2c0ce61ead72d9f (patch)
tree7c1b99b5ad53113aa9ae9cec8203a4c4dbc5119b /fs/f2fs
parent766c663933bec1068a6041f05bf31d39606bc2e8 (diff)
f2fs: fix to do sanity check on inode type during garbage collection
As report by Wenqing Liu in bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215231 - Overview kernel NULL pointer dereference triggered in folio_mark_dirty() when mount and operate on a crafted f2fs image - Reproduce tested on kernel 5.16-rc3, 5.15.X under root 1. mkdir mnt 2. mount -t f2fs tmp1.img mnt 3. touch tmp 4. cp tmp mnt F2FS-fs (loop0): sanity_check_inode: inode (ino=49) extent info [5942, 4294180864, 4] is incorrect, run fsck to fix F2FS-fs (loop0): f2fs_check_nid_range: out-of-range nid=31340049, run fsck to fix. BUG: kernel NULL pointer dereference, address: 0000000000000000 folio_mark_dirty+0x33/0x50 move_data_page+0x2dd/0x460 [f2fs] do_garbage_collect+0xc18/0x16a0 [f2fs] f2fs_gc+0x1d3/0xd90 [f2fs] f2fs_balance_fs+0x13a/0x570 [f2fs] f2fs_create+0x285/0x840 [f2fs] path_openat+0xe6d/0x1040 do_filp_open+0xc5/0x140 do_sys_openat2+0x23a/0x310 do_sys_open+0x57/0x80 The root cause is for special file: e.g. character, block, fifo or socket file, f2fs doesn't assign address space operations pointer array for mapping->a_ops field, so, in a fuzzed image, SSA table indicates a data block belong to special file, when f2fs tries to migrate that block, it causes NULL pointer access once move_data_page() calls a_ops->set_dirty_page(). Cc: stable@vger.kernel.org Reported-by: Wenqing Liu <wenqingliu0120@gmail.com> Signed-off-by: Chao Yu <chao@kernel.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs')
-rw-r--r--fs/f2fs/gc.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index a946ce0ead34..e0bdc4361a9b 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -1457,7 +1457,8 @@ next_step:
if (phase == 3) {
inode = f2fs_iget(sb, dni.ino);
- if (IS_ERR(inode) || is_bad_inode(inode))
+ if (IS_ERR(inode) || is_bad_inode(inode) ||
+ special_file(inode->i_mode))
continue;
if (!down_write_trylock(