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| author | Gao Xiang <hsiangkao@linux.alibaba.com> | 2023-04-10 20:37:14 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-05-11 17:03:06 +0300 |
| commit | 7ee7a86e28ce9ead7112286c388df8d254c373c6 (patch) | |
| tree | 46558b8d5caa827935e6d989f8117b0e0b8daf12 /fs/erofs | |
| parent | fe2f093b051c09cbf5ef416b987388e1d93e5ce0 (diff) | |
| download | linux-7ee7a86e28ce9ead7112286c388df8d254c373c6.tar.xz | |
erofs: stop parsing non-compact HEAD index if clusterofs is invalid
[ Upstream commit cc4efd3dd2ac9f89143e5d881609747ecff04164 ]
Syzbot generated a crafted image [1] with a non-compact HEAD index of
clusterofs 33024 while valid numbers should be 0 ~ lclustersize-1,
which causes the following unexpected behavior as below:
BUG: unable to handle page fault for address: fffff52101a3fff9
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 23ffed067 P4D 23ffed067 PUD 0
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 4398 Comm: kworker/u5:1 Not tainted 6.3.0-rc6-syzkaller-g09a9639e56c0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
Workqueue: erofs_worker z_erofs_decompressqueue_work
RIP: 0010:z_erofs_decompress_queue+0xb7e/0x2b40
...
Call Trace:
<TASK>
z_erofs_decompressqueue_work+0x99/0xe0
process_one_work+0x8f6/0x1170
worker_thread+0xa63/0x1210
kthread+0x270/0x300
ret_from_fork+0x1f/0x30
Note that normal images or images using compact indexes are not
impacted. Let's fix this now.
[1] https://lore.kernel.org/r/000000000000ec75b005ee97fbaa@google.com
Reported-and-tested-by: syzbot+aafb3f37cfeb6534c4ac@syzkaller.appspotmail.com
Fixes: 02827e1796b3 ("staging: erofs: add erofs_map_blocks_iter")
Fixes: 152a333a5895 ("staging: erofs: add compacted compression indexes support")
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20230410173714.104604-1-hsiangkao@linux.alibaba.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/erofs')
| -rw-r--r-- | fs/erofs/zmap.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c index 39cc014dba40..bb91cc649972 100644 --- a/fs/erofs/zmap.c +++ b/fs/erofs/zmap.c @@ -211,6 +211,10 @@ static int legacy_load_cluster_from_disk(struct z_erofs_maprecorder *m, if (advise & Z_EROFS_VLE_DI_PARTIAL_REF) m->partialref = true; m->clusterofs = le16_to_cpu(di->di_clusterofs); + if (m->clusterofs >= 1 << vi->z_logical_clusterbits) { + DBG_BUGON(1); + return -EFSCORRUPTED; + } m->pblk = le32_to_cpu(di->di_u.blkaddr); break; default: |