From: Eric Biggers <ebiggers@kernel.org>
To: Jaegeuk Kim <jaegeuk@kernel.org>, Chao Yu <chao@kernel.org>,
linux-f2fs-devel@lists.sourceforge.net
Cc: Daniel Rosenberg <drosen@google.com>,
Gabriel Krisman Bertazi <krisman@collabora.com>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
syzkaller-bugs@googlegroups.com,
syzbot+05139c4039d0679e19ff@syzkaller.appspotmail.com
Subject: [PATCH] f2fs: reject CASEFOLD inode flag without casefold feature
Date: Thu, 8 Oct 2020 12:15:22 -0700 [thread overview]
Message-ID: <20201008191522.1948889-1-ebiggers@kernel.org> (raw)
In-Reply-To: <00000000000085be6f05b12a1366@google.com>
From: Eric Biggers <ebiggers@google.com>
syzbot reported:
general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 PID: 6860 Comm: syz-executor835 Not tainted 5.9.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:utf8_casefold+0x43/0x1b0 fs/unicode/utf8-core.c:107
[...]
Call Trace:
f2fs_init_casefolded_name fs/f2fs/dir.c:85 [inline]
__f2fs_setup_filename fs/f2fs/dir.c:118 [inline]
f2fs_prepare_lookup+0x3bf/0x640 fs/f2fs/dir.c:163
f2fs_lookup+0x10d/0x920 fs/f2fs/namei.c:494
__lookup_hash+0x115/0x240 fs/namei.c:1445
filename_create+0x14b/0x630 fs/namei.c:3467
user_path_create fs/namei.c:3524 [inline]
do_mkdirat+0x56/0x310 fs/namei.c:3664
do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
[...]
The problem is that an inode has F2FS_CASEFOLD_FL set, but the
filesystem doesn't have the casefold feature flag set, and therefore
super_block::s_encoding is NULL.
Fix this by making sanity_check_inode() reject inodes that have
F2FS_CASEFOLD_FL when the filesystem doesn't have the casefold feature.
Reported-by: syzbot+05139c4039d0679e19ff@syzkaller.appspotmail.com
Fixes: 2c2eb7a300cd ("f2fs: Support case-insensitive file name lookups")
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
fs/f2fs/inode.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index 2ed935c13aed..d5664bc7d6c6 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -287,6 +287,13 @@ static bool sanity_check_inode(struct inode *inode, struct page *node_page)
return false;
}
+ if ((fi->i_flags & F2FS_CASEFOLD_FL) && !f2fs_sb_has_casefold(sbi)) {
+ set_sbi_flag(sbi, SBI_NEED_FSCK);
+ f2fs_warn(sbi, "%s: inode (ino=%lx) has casefold flag, but casefold feature is off",
+ __func__, inode->i_ino);
+ return false;
+ }
+
if (f2fs_has_extra_attr(inode) && f2fs_sb_has_compression(sbi) &&
fi->i_flags & F2FS_COMPR_FL &&
F2FS_FITS_IN_INODE(ri, fi->i_extra_isize,
base-commit: db40330b0de9a9d9939178f48cd5fc5e3fab14de
--
2.28.0.1011.ga647a8990f-goog
next prev parent reply other threads:[~2020-10-08 19:16 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-08 14:59 general protection fault in utf8_casefold syzbot
2020-10-08 19:15 ` Eric Biggers [this message]
2020-10-08 19:26 ` [PATCH] f2fs: reject CASEFOLD inode flag without casefold feature Gabriel Krisman Bertazi
2020-10-09 1:30 ` Chao Yu
2020-10-09 2:40 ` general protection fault in utf8_casefold syzbot
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