• Tetsuo Handa's avatar
    fs/dcache.c: fix kmemcheck splat at take_dentry_name_snapshot() · 6cd00a01
    Tetsuo Handa authored
    Since only dentry->d_name.len + 1 bytes out of DNAME_INLINE_LEN bytes
    are initialized at __d_alloc(), we can't copy the whole size
    unconditionally.
    
     WARNING: kmemcheck: Caught 32-bit read from uninitialized memory (ffff8fa27465ac50)
     636f6e66696766732e746d70000000000010000000000000020000000188ffff
      i i i i i i i i i i i i i u u u u u u u u u u i i i i i u u u u
                                      ^
     RIP: 0010:take_dentry_name_snapshot+0x28/0x50
     RSP: 0018:ffffa83000f5bdf8 EFLAGS: 00010246
     RAX: 0000000000000020 RBX: ffff8fa274b20550 RCX: 0000000000000002
     RDX: ffffa83000f5be40 RSI: ffff8fa27465ac50 RDI: ffffa83000f5be60
     RBP: ffffa83000f5bdf8 R08: ffffa83000f5be48 R09: 0000000000000001
     R10: ffff8fa27465ac00 R11: ffff8fa27465acc0 R12: ffff8fa27465ac00
     R13: ffff8fa27465acc0 R14: 0000000000000000 R15: 0000000000000000
     FS:  00007f79737ac8c0(0000) GS:ffffffff8fc30000(0000) knlGS:0000000000000000
     CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
     CR2: ffff8fa274c0b000 CR3: 0000000134aa7002 CR4: 00000000000606f0
      take_dentry_name_snapshot+0x28/0x50
      vfs_rename+0x128/0x870
      SyS_rename+0x3b2/0x3d0
      entry_SYSCALL_64_fastpath+0x1a/0xa4
      0xffffffffffffffff
    
    Link: http://lkml.kernel.org/r/201709131912.GBG39012.QMJLOVFSFFOOtH@I-love.SAKURA.ne.jpSigned-off-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
    Cc: Vegard Nossum <vegard.nossum@gmail.com>
    Cc: Al Viro <viro@zeniv.linux.org.uk>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    6cd00a01
dcache.c 81.7 KB