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...

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@linux.alibaba.com 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The error log is out-of-date since get_blocks() was removed long time ago.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@linux.alibaba.c... Fixes: ccd979bdbce9 ("[PATCH] OCFS2: The Second Oracle Cluster Filesystem") Signed-off-by: Joseph Qi joseph.qi@linux.alibaba.com Reported-by: syzbot+9709e73bae885b05314b@syzkaller.appspotmail.com Tested-by: syzbot+9709e73bae885b05314b@syzkaller.appspotmail.com Cc: Heming Zhao heming.zhao@suse.com Cc: Mark Fasheh mark@fasheh.com Cc: Joel Becker jlbec@evilplan.org Cc: Junxiao Bi junxiao.bi@oracle.com Cc: Changwei Ge gechangwei@live.cn Cc: Gang He ghe@suse.com Cc: Jun Piao piaojun@huawei.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

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@linux.alibaba.com are

ocfs2-fix-uninit-value-in-ocfs2_get_block.patch