• Johannes Thumshirn's avatar
    btrfs: free checksum hash on in close_ctree · bfcea1c6
    Johannes Thumshirn authored
    fs_info::csum_hash gets initialized in btrfs_init_csum_hash() which is
    called by open_ctree().
    
    But it only gets freed if open_ctree() fails, not on normal operation.
    
    This leads to a memory leak like the following found by kmemleak:
    unreferenced object 0xffff888132cb8720 (size 96):
    
      comm "mount", pid 450, jiffies 4294912436 (age 17.584s)
      hex dump (first 32 bytes):
        04 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
        00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
      backtrace:
        [<000000000c9643d4>] crypto_create_tfm+0x2d/0xd0
        [<00000000ae577f68>] crypto_alloc_tfm+0x4b/0xb0
        [<000000002b5cdf30>] open_ctree+0xb84/0x2060 [btrfs]
        [<0000000043204297>] btrfs_mount_root+0x552/0x640 [btrfs]
        [<00000000c99b10ea>] legacy_get_tree+0x22/0x40
        [<0000000071a6495f>] vfs_get_tree+0x1f/0xc0
        [<00000000f180080e>] fc_mount+0x9/0x30
        [<000000009e36cebd>] vfs_kern_mount.part.11+0x6a/0x80
        [<0000000004594c05>] btrfs_mount+0x174/0x910 [btrfs]
        [<00000000c99b10ea>] legacy_get_tree+0x22/0x40
        [<0000000071a6495f>] vfs_get_tree+0x1f/0xc0
        [<00000000b86e92c5>] do_mount+0x6b0/0x940
        [<0000000097464494>] ksys_mount+0x7b/0xd0
        [<0000000057213c80>] __x64_sys_mount+0x1c/0x20
        [<00000000cb689b5e>] do_syscall_64+0x43/0x130
        [<000000002194e289>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
    
    Free fs_info::csum_hash in close_ctree() to avoid the memory leak.
    
    Fixes: 6d97c6e3 ("btrfs: add boilerplate code for directly including the crypto framework")
    Reviewed-by: default avatarQu Wenruo <wqu@suse.com>
    Signed-off-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
    Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
    Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
    bfcea1c6
disk-io.c 126 KB