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f2fs: fix to do sanity check on block address in f2fs_do_zero_range()

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commit 25f8236213 upstream.

As Yanming reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=215894

I have encountered a bug in F2FS file system in kernel v5.17.

I have uploaded the system call sequence as case.c, and a fuzzed image can
be found in google net disk

The kernel should enable CONFIG_KASAN=y and CONFIG_KASAN_INLINE=y. You can
reproduce the bug by running the following commands:

kernel BUG at fs/f2fs/segment.c:2291!
Call Trace:
 f2fs_invalidate_blocks+0x193/0x2d0
 f2fs_fallocate+0x2593/0x4a70
 vfs_fallocate+0x2a5/0xac0
 ksys_fallocate+0x35/0x70
 __x64_sys_fallocate+0x8e/0xf0
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The root cause is, after image was fuzzed, block mapping info in inode
will be inconsistent with SIT table, so in f2fs_fallocate(), it will cause
panic when updating SIT with invalid blkaddr.

Let's fix the issue by adding sanity check on block address before updating
SIT table with it.

Cc: stable@vger.kernel.org
Reported-by: Ming Yan <yanming@tju.edu.cn>
Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Chao Yu 2022-04-27 17:51:40 +08:00 committed by Greg Kroah-Hartman
parent bce859358d
commit f2e1c38b5a
1 changed files with 12 additions and 4 deletions
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16
fs/f2fs/file.c
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@ -1436,11 +1436,19 @@ static int f2fs_do_zero_range(struct dnode_of_data *dn, pgoff_t start,
ret = -ENOSPC;
break;
}
if (dn->data_blkaddr != NEW_ADDR) {
f2fs_invalidate_blocks(sbi, dn->data_blkaddr);
dn->data_blkaddr = NEW_ADDR;
f2fs_set_data_blkaddr(dn);
if (dn->data_blkaddr == NEW_ADDR)
continue;
if (!f2fs_is_valid_blkaddr(sbi, dn->data_blkaddr,
DATA_GENERIC_ENHANCE)) {
ret = -EFSCORRUPTED;
break;
}
f2fs_invalidate_blocks(sbi, dn->data_blkaddr);
dn->data_blkaddr = NEW_ADDR;
f2fs_set_data_blkaddr(dn);
}
f2fs_update_extent_cache_range(dn, start, 0, index - start);