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authorRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>2012-03-17 04:08:39 +0400
committerWilly Tarreau <w@1wt.eu>2012-10-08 01:37:33 +0400
commit9d899d1facbd52795a6a94c667439000ab9f2bca (patch)
treebeeaf01fdbc8ab07577c119dc4f5d44d082ab118 /fs
parent3aeff2407453bf5f2c85b760df870f87df77c2e1 (diff)
downloadlinux-9d899d1facbd52795a6a94c667439000ab9f2bca.tar.xz
nilfs2: fix NULL pointer dereference in nilfs_load_super_block()
commit d7178c79d9b7c5518f9943188091a75fc6ce0675 upstream. 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] [<c0226636>] mount_fs+0x36/0x180 [<c023d961>] vfs_kern_mount+0x51/0xa0 [<c023ddae>] do_kern_mount+0x3e/0xe0 [<c023f189>] do_mount+0x169/0x700 [<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 <slicky.dvl@gmail.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Tested-by: Slicky Devil <slicky.dvl@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
Diffstat (limited to 'fs')
-rw-r--r--fs/nilfs2/the_nilfs.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index ad391a8c3e7e..149a8a141254 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -478,6 +478,7 @@ static int nilfs_load_super_block(struct the_nilfs *nilfs,
brelse(sbh[1]);
sbh[1] = NULL;
sbp[1] = NULL;
+ valid[1] = 0;
swp = 0;
}
if (!valid[swp]) {