diff options
| author | Chao Yu <chao@kernel.org> | 2022-09-14 19:51:51 +0800 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2022-10-04 13:31:43 -0700 |
| commit | c6ad7fd16657ebd34a87a97d9588195aae87597d (patch) | |
| tree | 0958700e5e66aa02b06af47425e0f3f7402043f1 /fs/f2fs/gc.c | |
| parent | 1e8a9191ccc286bbbfc1f9dccd31ac3bc9ec8a3f (diff) | |
f2fs: fix to do sanity check on summary info
As Wenqing Liu reported in bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=216456
BUG: KASAN: use-after-free in recover_data+0x63ae/0x6ae0 [f2fs]
Read of size 4 at addr ffff8881464dcd80 by task mount/1013
CPU: 3 PID: 1013 Comm: mount Tainted: G W 6.0.0-rc4 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
Call Trace:
dump_stack_lvl+0x45/0x5e
print_report.cold+0xf3/0x68d
kasan_report+0xa8/0x130
recover_data+0x63ae/0x6ae0 [f2fs]
f2fs_recover_fsync_data+0x120d/0x1fc0 [f2fs]
f2fs_fill_super+0x4665/0x61e0 [f2fs]
mount_bdev+0x2cf/0x3b0
legacy_get_tree+0xed/0x1d0
vfs_get_tree+0x81/0x2b0
path_mount+0x47e/0x19d0
do_mount+0xce/0xf0
__x64_sys_mount+0x12c/0x1a0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
The root cause is: in fuzzed image, SSA table is corrupted: ofs_in_node
is larger than ADDRS_PER_PAGE(), result in out-of-range access on 4k-size
page.
- recover_data
- do_recover_data
- check_index_in_prev_nodes
- f2fs_data_blkaddr
This patch adds sanity check on summary info in recovery and GC flow
in where the flows rely on them.
After patch:
[ 29.310883] F2FS-fs (loop0): Inconsistent ofs_in_node:65286 in summary, ino:0, nid:6, max:1018
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/gc.c')
| -rw-r--r-- | fs/f2fs/gc.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index fd400d148afb..3a820e5cdaee 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -1078,7 +1078,7 @@ static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, { struct page *node_page; nid_t nid; - unsigned int ofs_in_node; + unsigned int ofs_in_node, max_addrs; block_t source_blkaddr; nid = le32_to_cpu(sum->nid); @@ -1104,6 +1104,14 @@ static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, return false; } + max_addrs = IS_INODE(node_page) ? DEF_ADDRS_PER_INODE : + DEF_ADDRS_PER_BLOCK; + if (ofs_in_node >= max_addrs) { + f2fs_err(sbi, "Inconsistent ofs_in_node:%u in summary, ino:%u, nid:%u, max:%u", + ofs_in_node, dni->ino, dni->nid, max_addrs); + return false; + } + *nofs = ofs_of_node(node_page); source_blkaddr = data_blkaddr(NULL, node_page, ofs_in_node); f2fs_put_page(node_page, 1); |