The patch titled
Subject: ocfs2: fix uninit-value in ocfs2_get_block()
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
ocfs2-fix-uninit-value-in-ocfs2_get_block.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/ocfs2-fix-uninit-value-in-ocfs2_get_block.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx>
Subject: ocfs2: fix uninit-value in ocfs2_get_block()
Date: Wed, 25 Sep 2024 17:06:00 +0800
syzbot reported an uninit-value BUG:
BUG: KMSAN: uninit-value in ocfs2_get_block+0xed2/0x2710 fs/ocfs2/aops.c:159
ocfs2_get_block+0xed2/0x2710 fs/ocfs2/aops.c:159
do_mpage_readpage+0xc45/0x2780 fs/mpage.c:225
mpage_readahead+0x43f/0x840 fs/mpage.c:374
ocfs2_readahead+0x269/0x320 fs/ocfs2/aops.c:381
read_pages+0x193/0x1110 mm/readahead.c:160
page_cache_ra_unbounded+0x901/0x9f0 mm/readahead.c:273
do_page_cache_ra mm/readahead.c:303 [inline]
force_page_cache_ra+0x3b1/0x4b0 mm/readahead.c:332
force_page_cache_readahead mm/internal.h:347 [inline]
generic_fadvise+0x6b0/0xa90 mm/fadvise.c:106
vfs_fadvise mm/fadvise.c:185 [inline]
ksys_fadvise64_64 mm/fadvise.c:199 [inline]
__do_sys_fadvise64 mm/fadvise.c:214 [inline]
__se_sys_fadvise64 mm/fadvise.c:212 [inline]
__x64_sys_fadvise64+0x1fb/0x3a0 mm/fadvise.c:212
x64_sys_call+0xe11/0x3ba0
arch/x86/include/generated/asm/syscalls_64.h:222
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
This is because when ocfs2_extent_map_get_blocks() fails, p_blkno is
uninitialized. So the error log will trigger the above uninit-value
access.
The error log is out-of-date since get_blocks() was removed long time ago.
And the error code will be logged in ocfs2_extent_map_get_blocks() once
ocfs2_get_cluster() fails, so fix this by only logging inode and block.
Link: https://syzkaller.appspot.com/bug?extid=9709e73bae885b05314b
Link: https://lkml.kernel.org/r/20240925090600.3643376-1-joseph.qi@xxxxxxxxxxxxxxxxx
Fixes: ccd979bdbce9 ("[PATCH] OCFS2: The Second Oracle Cluster Filesystem")
Signed-off-by: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx>
Reported-by: syzbot+9709e73bae885b05314b@xxxxxxxxxxxxxxxxxxxxxxxxx
Tested-by: syzbot+9709e73bae885b05314b@xxxxxxxxxxxxxxxxxxxxxxxxx
Cc: Heming Zhao <heming.zhao@xxxxxxxx>
Cc: Mark Fasheh <mark@xxxxxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Cc: Junxiao Bi <junxiao.bi@xxxxxxxxxx>
Cc: Changwei Ge <gechangwei@xxxxxxx>
Cc: Gang He <ghe@xxxxxxxx>
Cc: Jun Piao <piaojun@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/ocfs2/aops.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
--- a/fs/ocfs2/aops.c~ocfs2-fix-uninit-value-in-ocfs2_get_block
+++ a/fs/ocfs2/aops.c
@@ -156,9 +156,8 @@ int ocfs2_get_block(struct inode *inode,
err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, &count,
&ext_flags);
if (err) {
- mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
- "%llu, NULL)\n", err, inode, (unsigned long long)iblock,
- (unsigned long long)p_blkno);
+ mlog(ML_ERROR, "get_blocks() failed, inode: 0x%p, "
+ "block: %llu\n", inode, (unsigned long long)iblock);
goto bail;
}
_
Patches currently in -mm which might be from joseph.qi@xxxxxxxxxxxxxxxxx are
ocfs2-fix-uninit-value-in-ocfs2_get_block.patch
