-stable review patch. If anyone has any objections, please let us know. ------------------ From: Michal Miroslaw Fix BUG I tripped on while testing failover and multipathing. BUG shows up on error path in multipath_ctr() when parse_priority_group() fails after returning at least once without error. The fix is to initialize m->ti early - just after alloc()ing it. BUG: unable to handle kernel NULL pointer dereference at virtual address 00000000 printing eip: c027c3d2 *pde = 00000000 Oops: 0000 [#3] Modules linked in: qla2xxx ext3 jbd mbcache sg ide_cd cdrom floppy CPU: 0 EIP: 0060:[] Not tainted VLI EFLAGS: 00010202 (2.6.17.3 #1) EIP is at dm_put_device+0xf/0x3b eax: 00000001 ebx: ee4fcac0 ecx: 00000000 edx: ee4fcac0 esi: ee4fc4e0 edi: ee4fc4e0 ebp: 00000000 esp: c5db3e78 ds: 007b es: 007b ss: 0068 Process multipathd (pid: 15912, threadinfo=c5db2000 task=ef485a90) Stack: ec4eda40 c02816bd ee4fc4c0 00000000 f7e89498 f883e0bc c02816f6 f7e89480 f7e8948c c0281801 ffffffea f7e89480 f883e080 c0281ffe 00000001 00000000 00000004 dfe9cab8 f7a693c0 f883e080 f883e0c0 ca4b99c0 c027c6ee 01400000 Call Trace: free_pgpaths+0x31/0x45 free_priority_group+0x25/0x2e free_multipath+0x35/0x67 multipath_ctr+0x123/0x12d dm_table_add_target+0x11e/0x18b populate_table+0x8a/0xaf table_load+0x52/0xf9 ctl_ioctl+0xca/0xfc table_load+0x0/0xf9 do_ioctl+0x3e/0x43 vfs_ioctl+0x16c/0x178 sys_ioctl+0x48/0x60 syscall_call+0x7/0xb Code: 97 f0 00 00 00 89 c1 83 c9 01 80 e2 01 0f 44 c1 88 43 14 8b 04 24 59 5b 5e 5f 5d c3 53 89 c1 89 d3 ff 4a 08 0f 94 c0 84 c0 74 2a <8b> 01 8b 10 89 d8 e8 f6 fb ff ff 8b 03 8b 53 04 89 50 04 89 02 EIP: [] dm_put_device+0xf/0x3b SS:ESP 0068:c5db3e78 Signed-off-by: Michal Miroslaw Acked-by: Alasdair G Kergon Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-mpath.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- linux-2.6.17.9.orig/drivers/md/dm-mpath.c +++ linux-2.6.17.9/drivers/md/dm-mpath.c @@ -711,6 +711,8 @@ static int multipath_ctr(struct dm_targe return -EINVAL; } + m->ti = ti; + r = parse_features(&as, m, ti); if (r) goto bad; @@ -752,7 +754,6 @@ static int multipath_ctr(struct dm_targe } ti->private = m; - m->ti = ti; return 0; -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/