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    ovl: fix access beyond unterminated strings · 601350ff
    Amir Goldstein 提交于
    KASAN detected slab-out-of-bounds access in printk from overlayfs,
    because string format used %*s instead of %.*s.
    
    > BUG: KASAN: slab-out-of-bounds in string+0x298/0x2d0 lib/vsprintf.c:604
    > Read of size 1 at addr ffff8801c36c66ba by task syz-executor2/27811
    >
    > CPU: 0 PID: 27811 Comm: syz-executor2 Not tainted 4.19.0-rc5+ #36
    ...
    >  printk+0xa7/0xcf kernel/printk/printk.c:1996
    >  ovl_lookup_index.cold.15+0xe8/0x1f8 fs/overlayfs/namei.c:689
    
    Reported-by: syzbot+376cea2b0ef340db3dd4@syzkaller.appspotmail.com
    Signed-off-by: NAmir Goldstein <amir73il@gmail.com>
    Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
    Fixes: 359f392c ("ovl: lookup index entry for copy up origin")
    Cc: <stable@vger.kernel.org> # v4.13
    601350ff
namei.c 27.0 KB