The patch titled
     Subject: nilfs2: fix NULL pointer dereference in nilfs_load_super_block()
has been added to the -mm tree.  Its filename is
     nilfs2-fix-null-pointer-dereference-in-nilfs_load_super_block.patch

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------------------------------------------------------
From: Ryusuke Konishi <[email protected]>
Subject: nilfs2: fix NULL pointer dereference in nilfs_load_super_block()

According to the report from Slicky Devil, nilfs caused kernel oops at
nilfs_load_super_block function during mount after he shrank the partition
without resizing the filesystem:

 BUG: unable to handle kernel NULL pointer dereference at 00000048
 IP: [<d0d7a08e>] nilfs_load_super_block+0x17e/0x280 [nilfs2]
 *pde = 00000000
 Oops: 0000 [#1] PREEMPT SMP
 ...
 Call Trace:
  [<d0d7a87b>] init_nilfs+0x4b/0x2e0 [nilfs2]
  [<d0d6f707>] nilfs_mount+0x447/0x5b0 [nilfs2]
  [<c01f33a4>] ? pcpu_alloc+0x714/0x810
  [<c02d2add>] ? ida_get_new_above+0x1ad/0x230
  [<c02d2add>] ? ida_get_new_above+0x1ad/0x230
  [<c0226636>] mount_fs+0x36/0x180
  [<c01f34af>] ? __alloc_percpu+0xf/0x20
  [<c023d961>] vfs_kern_mount+0x51/0xa0
  [<c023ddae>] do_kern_mount+0x3e/0xe0
  [<c023f189>] do_mount+0x169/0x700
  [<c01eeb29>] ? strndup_user+0x49/0x70
  [<c023fa9b>] sys_mount+0x6b/0xa0
  [<c04abd1f>] sysenter_do_call+0x12/0x28
 Code: 53 18 8b 43 20 89 4b 18 8b 4b 24 89 53 1c 89 43 24 89 4b 20 8b 43
 20 c7 43 2c 00 00 00 00 23 75 e8 8b 50 68 89 53 28 8b 54 b3 20 <8b> 72
 48 8b 7a 4c 8b 55 08 89 b3 84 00 00 00 89 bb 88 00 00 00
 EIP: [<d0d7a08e>] nilfs_load_super_block+0x17e/0x280 [nilfs2] SS:ESP 
0068:ca9bbdcc
 CR2: 0000000000000048

This turned out due to a defect in an error path which runs if the
calculated location of the secondary super block was invalid.

This patch fixes it and eliminates the reported oops.

Reported-by: Slicky Devil <[email protected]>
Signed-off-by: Ryusuke Konishi <[email protected]>
Tested-by: Slicky Devil <[email protected]>
Cc: <[email protected]>    [2.6.30+]
Signed-off-by: Andrew Morton <[email protected]>
---

 fs/nilfs2/the_nilfs.c |    1 +
 1 file changed, 1 insertion(+)

diff -puN 
fs/nilfs2/the_nilfs.c~nilfs2-fix-null-pointer-dereference-in-nilfs_load_super_block
 fs/nilfs2/the_nilfs.c
--- 
a/fs/nilfs2/the_nilfs.c~nilfs2-fix-null-pointer-dereference-in-nilfs_load_super_block
+++ a/fs/nilfs2/the_nilfs.c
@@ -521,6 +521,7 @@ static int nilfs_load_super_block(struct
                brelse(sbh[1]);
                sbh[1] = NULL;
                sbp[1] = NULL;
+               valid[1] = 0;
                swp = 0;
        }
        if (!valid[swp]) {
_
Subject: Subject: nilfs2: fix NULL pointer dereference in 
nilfs_load_super_block()

Patches currently in -mm which might be from [email protected] are

nilfs2-clamp-ns_r_segments_percentage-to.patch
nilfs2-fix-null-pointer-dereference-in-nilfs_load_super_block.patch
linux-next.patch

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