• T
    ext4: avoid a potential slab-out-of-bounds in ext4_group_desc_csum · 0d4053b9
    Tudor Ambarus 提交于
    stable inclusion
    from stable-v5.10.180
    commit 0dde3141c527b09b96bef1e7eeb18b8127810ce9
    category: bugfix
    bugzilla: 188791,https://gitee.com/openeuler/kernel/issues/I76XUJ
    
    Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=0dde3141c527b09b96bef1e7eeb18b8127810ce9
    
    --------------------------------
    
    commit 4f043518 upstream.
    
    When modifying the block device while it is mounted by the filesystem,
    syzbot reported the following:
    
    BUG: KASAN: slab-out-of-bounds in crc16+0x206/0x280 lib/crc16.c:58
    Read of size 1 at addr ffff888075f5c0a8 by task syz-executor.2/15586
    
    CPU: 1 PID: 15586 Comm: syz-executor.2 Not tainted 6.2.0-rc5-syzkaller-00205-gc9661827 #0
    Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
    Call Trace:
     <TASK>
     __dump_stack lib/dump_stack.c:88 [inline]
     dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106
     print_address_description+0x74/0x340 mm/kasan/report.c:306
     print_report+0x107/0x1f0 mm/kasan/report.c:417
     kasan_report+0xcd/0x100 mm/kasan/report.c:517
     crc16+0x206/0x280 lib/crc16.c:58
     ext4_group_desc_csum+0x81b/0xb20 fs/ext4/super.c:3187
     ext4_group_desc_csum_set+0x195/0x230 fs/ext4/super.c:3210
     ext4_mb_clear_bb fs/ext4/mballoc.c:6027 [inline]
     ext4_free_blocks+0x191a/0x2810 fs/ext4/mballoc.c:6173
     ext4_remove_blocks fs/ext4/extents.c:2527 [inline]
     ext4_ext_rm_leaf fs/ext4/extents.c:2710 [inline]
     ext4_ext_remove_space+0x24ef/0x46a0 fs/ext4/extents.c:2958
     ext4_ext_truncate+0x177/0x220 fs/ext4/extents.c:4416
     ext4_truncate+0xa6a/0xea0 fs/ext4/inode.c:4342
     ext4_setattr+0x10c8/0x1930 fs/ext4/inode.c:5622
     notify_change+0xe50/0x1100 fs/attr.c:482
     do_truncate+0x200/0x2f0 fs/open.c:65
     handle_truncate fs/namei.c:3216 [inline]
     do_open fs/namei.c:3561 [inline]
     path_openat+0x272b/0x2dd0 fs/namei.c:3714
     do_filp_open+0x264/0x4f0 fs/namei.c:3741
     do_sys_openat2+0x124/0x4e0 fs/open.c:1310
     do_sys_open fs/open.c:1326 [inline]
     __do_sys_creat fs/open.c:1402 [inline]
     __se_sys_creat fs/open.c:1396 [inline]
     __x64_sys_creat+0x11f/0x160 fs/open.c:1396
     do_syscall_x64 arch/x86/entry/common.c:50 [inline]
     do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
     entry_SYSCALL_64_after_hwframe+0x63/0xcd
    RIP: 0033:0x7f72f8a8c0c9
    Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
    RSP: 002b:00007f72f97e3168 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
    RAX: ffffffffffffffda RBX: 00007f72f8bac050 RCX: 00007f72f8a8c0c9
    RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000280
    RBP: 00007f72f8ae7ae9 R08: 0000000000000000 R09: 0000000000000000
    R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
    R13: 00007ffd165348bf R14: 00007f72f97e3300 R15: 0000000000022000
    
    Replace
    	le16_to_cpu(sbi->s_es->s_desc_size)
    with
    	sbi->s_desc_size
    
    It reduces ext4's compiled text size, and makes the code more efficient
    (we remove an extra indirect reference and a potential byte
    swap on big endian systems), and there is no downside. It also avoids the
    potential KASAN / syzkaller failure, as a bonus.
    
    Reported-by: syzbot+fc51227e7100c9294894@syzkaller.appspotmail.com
    Reported-by: syzbot+8785e41224a3afd04321@syzkaller.appspotmail.com
    Link: https://syzkaller.appspot.com/bug?id=70d28d11ab14bd7938f3e088365252aa923cff42
    Link: https://syzkaller.appspot.com/bug?id=b85721b38583ecc6b5e72ff524c67302abbc30f3
    Link: https://lore.kernel.org/all/000000000000ece18705f3b20934@google.com/
    Fixes: 717d50e4 ("Ext4: Uninitialized Block Groups")
    Cc: stable@vger.kernel.org
    Signed-off-by: NTudor Ambarus <tudor.ambarus@linaro.org>
    Link: https://lore.kernel.org/r/20230504121525.3275886-1-tudor.ambarus@linaro.orgSigned-off-by: NTheodore Ts'o <tytso@mit.edu>
    Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    Signed-off-by: NBaokun Li <libaokun1@huawei.com>
    Reviewed-by: NYang Erkun <yangerkun@huawei.com>
    Signed-off-by: NJialin Zhang <zhangjialin11@huawei.com>
    0d4053b9
super.c 196.5 KB