From: Chao Yu <chao@kernel.org>
To: jaegeuk@kernel.org
Cc: Wenqing Liu <wenqingliu0120@gmail.com>,
linux-kernel@vger.kernel.org, stable@vger.kernel.org,
linux-f2fs-devel@lists.sourceforge.net
Subject: [f2fs-dev] [PATCH 1/3] f2fs: fix to do sanity check on inode type during garbage collection
Date: Mon, 6 Dec 2021 22:44:19 +0800 [thread overview]
Message-ID: <20211206144421.3735-1-chao@kernel.org> (raw)
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>
---
fs/f2fs/gc.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
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 @@ static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
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(
--
2.32.0
_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
next reply other threads:[~2021-12-06 14:44 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-06 14:44 Chao Yu [this message]
2021-12-06 14:44 ` [f2fs-dev] [PATCH 2/3] f2fs: fix to avoid panic in is_alive() if metadata is inconsistent Chao Yu
2021-12-06 14:44 ` [f2fs-dev] [PATCH 3/3] f2fs: fix to do sanity check in is_alive() Chao Yu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20211206144421.3735-1-chao@kernel.org \
--to=chao@kernel.org \
--cc=jaegeuk@kernel.org \
--cc=linux-f2fs-devel@lists.sourceforge.net \
--cc=linux-kernel@vger.kernel.org \
--cc=stable@vger.kernel.org \
--cc=wenqingliu0120@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).