• Joseph Qi's avatar
    ocfs2: fix uninit-value in ocfs2_get_block() · 2af148ef
    Joseph Qi authored
    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    The error log is out-of-date since get_blocks() was removed long time ago.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.com
    Fixes: ccd979bd ("[PATCH] OCFS2: The Second Oracle Cluster Filesystem")
    Signed-off-by: default avatarJoseph 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: default avatarAndrew Morton <akpm@linux-foundation.org>
    2af148ef
aops.c 62.3 KB