| Message ID | 20110509140411.GJ1661@htj.dyndns.org |
|---|---|
| State | Not Applicable |
| Delegated to: | David Miller |
| Headers | show |
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index f26f2fe..dad9fd6 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -3316,7 +3316,7 @@ static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy, struct ata_eh_context *ehc = &link->eh_context; struct ata_device *dev, *link_dev = NULL, *lpm_dev = NULL; enum ata_lpm_policy old_policy = link->lpm_policy; - bool no_dipm = ap->flags & ATA_FLAG_NO_DIPM; + bool no_dipm = link->ap->flags & ATA_FLAG_NO_DIPM; unsigned int hints = ATA_LPM_EMPTY | ATA_LPM_HIPM; unsigned int err_mask; int rc;
ae01b2493c (libata: Implement ATA_FLAG_NO_DIPM and apply it to mcp65) added ATA_FLAG_NO_DIPM and made ata_eh_set_lpm() check the flag. However, @ap is NULL if @link points to a PMP link and thus the unconditional @ap->flags dereference leads to the following oops. BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 IP: [<ffffffff813f98e1>] ata_eh_recover+0x9a1/0x1510 ... Pid: 295, comm: scsi_eh_4 Tainted: P 2.6.38.5-core2 #1 System76, Inc. Serval Professional/Serval Professional RIP: 0010:[<ffffffff813f98e1>] [<ffffffff813f98e1>] ata_eh_recover+0x9a1/0x1510 RSP: 0018:ffff880132defbf0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff880132f40000 RCX: 0000000000000000 RDX: ffff88013377c000 RSI: ffff880132f40000 RDI: 0000000000000000 RBP: ffff880132defce0 R08: ffff88013377dc58 R09: ffff880132defd98 R10: 0000000000000000 R11: 00000000ffffffff R12: 0000000000000000 R13: 0000000000000000 R14: ffff88013377c000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8800bf700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000018 CR3: 0000000001a03000 CR4: 00000000000406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process scsi_eh_4 (pid: 295, threadinfo ffff880132dee000, task ffff880133b416c0) Stack: 0000000000000000 ffff880132defcc0 0000000000000000 ffff880132f42738 ffffffff813ee8f0 ffffffff813eefe0 ffff880132defd98 ffff88013377f190 ffffffffa00b3e30 ffffffff813ef030 0000000032defc60 ffff880100000000 Call Trace: [<ffffffff81400867>] sata_pmp_error_handler+0x607/0xc30 [<ffffffffa00b273f>] ahci_error_handler+0x1f/0x70 [libahci] [<ffffffff813faade>] ata_scsi_error+0x5be/0x900 [<ffffffff813cf724>] scsi_error_handler+0x124/0x650 [<ffffffff810834b6>] kthread+0x96/0xa0 [<ffffffff8100cd64>] kernel_thread_helper+0x4/0x10 Code: 8b 95 70 ff ff ff b8 00 00 00 00 48 3b 9a 10 2e 00 00 48 0f 44 c2 48 89 85 70 ff ff ff 48 8b 8d 70 ff ff ff f6 83 69 02 00 00 01 <48> 8b 41 18 0f 85 48 01 00 00 48 85 c9 74 12 48 8b 51 08 48 83 RIP [<ffffffff813f98e1>] ata_eh_recover+0x9a1/0x1510 RSP <ffff880132defbf0> CR2: 0000000000000018 Fix it by testing @link->ap->flags instead. stable: ATA_FLAG_NO_DIPM was added during 2.6.39 cycle but was backported to 2.6.37 and 38. This is a fix for that and thus also applicable to 2.6.37 and 38. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: "Nathan A. Mourey II" <nmoureyii@ne.rr.com> LKML-Reference: <1304555277.2059.2.camel@localhost.localdomain> Cc: Connor H <cmdkhh@gmail.com> Cc: stable@kernel.org --- Nathan, thanks a lot for the report. Connor, thanks for the analysis but it was a bit off. :-) drivers/ata/libata-eh.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html