Hi everyone,
I can't mount ext4 in linux-next:
[ 10.308422] BUG: unable to handle kernel NULL pointer dereference at
0000000000000012
[ 10.324470] IP: [<ffffffff81265e86>] ext4_fill_super+0x2336/0x3180
[ 10.337045] PGD 0
[ 10.341296] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
[ 10.350786] Modules linked in: megaraid_sas
[ 10.359479] CPU: 8 PID: 2917 Comm: mount Not tainted
3.18.0-rc7-next-20141205-mason+ #17
[ 10.375846] Hardware name: ZTSYSTEMS Echo Ridge T4 /A9DRPF-10D,
BIOS 1.07 05/10/2012
[ 10.391691] task: ffff880848d4c3d0 ti: ffff880848a7c000 task.ti:
ffff880848a7c000
[ 10.406841] RIP: 0010:[<ffffffff81265e86>] [<ffffffff81265e86>]
ext4_fill_super+0x2336/0x3180
[ 10.424340] RSP: 0018:ffff880848a7fc68 EFLAGS: 00010246
[ 10.435075] RAX: ffff88104b1a7000 RBX: ffff881054d86800 RCX:
0000000000000000
[ 10.449472] RDX: 000000000452beff RSI: 00000000000001d1 RDI:
0000000000083f99
[ 10.463862] RBP: ffff880848a7fd58 R08: 0000000000000000 R09:
0000000000000002
[ 10.478252] R10: 0000000000000000 R11: 0000000000000001 R12:
ffff88104b1a7000
[ 10.492640] R13: 00000000000008a6 R14: 0000000000000080 R15:
ffff881046905400
[ 10.507031] FS: 00007f3d24e2f7e0(0000) GS:ffff881075e00000(0000)
knlGS:0000000000000000
[ 10.523400] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 10.535012] CR2: 0000000000000012 CR3: 0000001040a75000 CR4:
00000000000407e0
[ 10.549405] Stack:
[ 10.553566] 0000000000000020 ffff880848a7fd88 ffff881046906fe0
ffff88104573bf80
[ 10.568938] 0000001254d86800 ffff880848a7fd88 ffff88084a53f801
00000000000008a6
[ 10.584315] 0000000000000012 ffff88104b1a7000 0000000000000000
0000000000000000
[ 10.599693] Call Trace:
[ 10.604726] [<ffffffff8109fb5d>] ?
trace_hardirqs_on_caller+0x10d/0x1d0
[ 10.618242] [<ffffffff811b3ac2>] mount_bdev+0x1a2/0x1e0
[ 10.628991] [<ffffffff8116e783>] ? pcpu_alloc+0x353/0x660
[ 10.640088] [<ffffffff81263b50>] ?
ext4_alloc_flex_bg_array+0x120/0x120
[ 10.653624] [<ffffffff81255a75>] ext4_mount+0x15/0x20
[ 10.664018] [<ffffffff811b3633>] mount_fs+0x43/0x1b0
[ 10.674234] [<ffffffff8116eac5>] ? __alloc_percpu+0x15/0x20
[ 10.685666] [<ffffffff811d35b6>] vfs_kern_mount+0x76/0x160
[ 10.696939] [<ffffffff811d42a7>] do_mount+0x237/0xab0
[ 10.707344] [<ffffffff811774f6>] ? might_fault+0x66/0xc0
[ 10.718254] [<ffffffff811d4b9b>] SyS_mount+0x7b/0xc0
[ 10.728471] [<ffffffff816629d2>] system_call_fastpath+0x12/0x17
[ 10.740612] Code: 60 ff ff ff 4c 8b a5 58 ff ff ff 44 89 f1 48 c7 c2
20 6a a2 81 48 c7 c6 de 95 9f 81 48 89 df 31 c0 e8 4f 24 ff ff e9 50 f1
ff ff <f6> 41 12 04 45 0f 44 ee e9 60 ef ff ff 44 8b ad 60 ff ff ff 4c
(gdb) list *ext4_fill_super+0x2336
0xffffffff81265e86 is in ext4_fill_super (fs/ext4/super.c:2082).
2077 last_block = ext4_blocks_count(sbi->s_es) - 1;
2078 else
2079 last_block = first_block +
2080 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2081
2082 if ((grp == sbi->s_groups_count) &&
2083 !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
^^^^^^^^^^^^^^^^^^^^^^^^
2084 grp = i;
2085
2086 block_bitmap = ext4_block_bitmap(sb, gdp);
Looks like gdp is NULL.
I reverted this one:
commit fdfe073987619ec375da8d8a2701ab271d1b1339
Author: Dmitry Monakhov <dmonakhov@xxxxxxxxxx>
Date: Tue Dec 2 16:09:16 2014 -0500
ext4: fix potential use after free during resize
And I can mount again. A quick look at the archives show that Sergey
hit the same thing, so I've cc'd him.
-chris
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
