• Y
    ext4: fix uninititialized value in 'ext4_evict_inode' · 7e9b214f
    Ye Bin 提交于
    stable inclusion
    from stable-v5.10.164
    commit 091f85db4c3fb1734a6d7fb4777a2b2831da6631
    category: bugfix
    bugzilla: https://gitee.com/openeuler/kernel/issues/I7T7G4
    
    Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=091f85db4c3fb1734a6d7fb4777a2b2831da6631
    
    --------------------------------
    
    [ Upstream commit 7ea71af9 ]
    
    Syzbot found the following issue:
    =====================================================
    BUG: KMSAN: uninit-value in ext4_evict_inode+0xdd/0x26b0 fs/ext4/inode.c:180
     ext4_evict_inode+0xdd/0x26b0 fs/ext4/inode.c:180
     evict+0x365/0x9a0 fs/inode.c:664
     iput_final fs/inode.c:1747 [inline]
     iput+0x985/0xdd0 fs/inode.c:1773
     __ext4_new_inode+0xe54/0x7ec0 fs/ext4/ialloc.c:1361
     ext4_mknod+0x376/0x840 fs/ext4/namei.c:2844
     vfs_mknod+0x79d/0x830 fs/namei.c:3914
     do_mknodat+0x47d/0xaa0
     __do_sys_mknodat fs/namei.c:3992 [inline]
     __se_sys_mknodat fs/namei.c:3989 [inline]
     __ia32_sys_mknodat+0xeb/0x150 fs/namei.c:3989
     do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
     __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
     do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203
     do_SYSENTER_32+0x1b/0x20 arch/x86/entry/common.c:246
     entry_SYSENTER_compat_after_hwframe+0x70/0x82
    
    Uninit was created at:
     __alloc_pages+0x9f1/0xe80 mm/page_alloc.c:5578
     alloc_pages+0xaae/0xd80 mm/mempolicy.c:2285
     alloc_slab_page mm/slub.c:1794 [inline]
     allocate_slab+0x1b5/0x1010 mm/slub.c:1939
     new_slab mm/slub.c:1992 [inline]
     ___slab_alloc+0x10c3/0x2d60 mm/slub.c:3180
     __slab_alloc mm/slub.c:3279 [inline]
     slab_alloc_node mm/slub.c:3364 [inline]
     slab_alloc mm/slub.c:3406 [inline]
     __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
     kmem_cache_alloc_lru+0x6f3/0xb30 mm/slub.c:3429
     alloc_inode_sb include/linux/fs.h:3117 [inline]
     ext4_alloc_inode+0x5f/0x860 fs/ext4/super.c:1321
     alloc_inode+0x83/0x440 fs/inode.c:259
     new_inode_pseudo fs/inode.c:1018 [inline]
     new_inode+0x3b/0x430 fs/inode.c:1046
     __ext4_new_inode+0x2a7/0x7ec0 fs/ext4/ialloc.c:959
     ext4_mkdir+0x4d5/0x1560 fs/ext4/namei.c:2992
     vfs_mkdir+0x62a/0x870 fs/namei.c:4035
     do_mkdirat+0x466/0x7b0 fs/namei.c:4060
     __do_sys_mkdirat fs/namei.c:4075 [inline]
     __se_sys_mkdirat fs/namei.c:4073 [inline]
     __ia32_sys_mkdirat+0xc4/0x120 fs/namei.c:4073
     do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
     __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
     do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203
     do_SYSENTER_32+0x1b/0x20 arch/x86/entry/common.c:246
     entry_SYSENTER_compat_after_hwframe+0x70/0x82
    
    CPU: 1 PID: 4625 Comm: syz-executor.2 Not tainted 6.1.0-rc4-syzkaller-62821-gcb231e2f67ec #0
    Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
    =====================================================
    
    Now, 'ext4_alloc_inode()' didn't init 'ei->i_flags'. If new inode failed
    before set 'ei->i_flags' in '__ext4_new_inode()', then do 'iput()'. As after
    6bc0d63d commit will access 'ei->i_flags' in 'ext4_evict_inode()' which
    will lead to access uninit-value.
    To solve above issue just init 'ei->i_flags' in 'ext4_alloc_inode()'.
    
    Reported-by: syzbot+57b25da729eb0b88177d@syzkaller.appspotmail.com
    Signed-off-by: NYe Bin <yebin10@huawei.com>
    Fixes: 6bc0d63d ("ext4: remove EA inode entry from mbcache on inode eviction")
    Reviewed-by: NJan Kara <jack@suse.cz>
    Reviewed-by: NEric Biggers <ebiggers@google.com>
    Link: https://lore.kernel.org/r/20221117073603.2598882-1-yebin@huaweicloud.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>
    Cc: stable@kernel.org
    Signed-off-by: NSasha Levin <sashal@kernel.org>
    Signed-off-by: Nsanglipeng <sanglipeng1@jd.com>
    7e9b214f
super.c 196.6 KB