• Chao Yu's avatar
    f2fs: fix to do sanity check on block address in f2fs_do_zero_range() · 25f82362
    Chao Yu authored
    As Yanming reported in bugzilla:
    
    https://bugzilla.kernel.org/show_bug.cgi?id=215894
    
    I have encountered a bug in F2FS file system in kernel v5.17.
    
    I have uploaded the system call sequence as case.c, and a fuzzed image can
    be found in google net disk
    
    The kernel should enable CONFIG_KASAN=y and CONFIG_KASAN_INLINE=y. You can
    reproduce the bug by running the following commands:
    
    kernel BUG at fs/f2fs/segment.c:2291!
    Call Trace:
     f2fs_invalidate_blocks+0x193/0x2d0
     f2fs_fallocate+0x2593/0x4a70
     vfs_fallocate+0x2a5/0xac0
     ksys_fallocate+0x35/0x70
     __x64_sys_fallocate+0x8e/0xf0
     do_syscall_64+0x3b/0x90
     entry_SYSCALL_64_after_hwframe+0x44/0xae
    
    The root cause is, after image was fuzzed, block mapping info in inode
    will be inconsistent with SIT table, so in f2fs_fallocate(), it will cause
    panic when updating SIT with invalid blkaddr.
    
    Let's fix the issue by adding sanity check on block address before updating
    SIT table with it.
    
    Cc: stable@vger.kernel.org
    Reported-by: default avatarMing Yan <yanming@tju.edu.cn>
    Signed-off-by: default avatarChao Yu <chao.yu@oppo.com>
    Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
    25f82362
file.c 117 KB