[PATCH] aacraid: fix shutdown crash when init fails

[PATCH] aacraid: fix shutdown crash when init fails

[Meelis Roos]

When aacraid init fails with "AAC0: adapter self-test failed.", shutdown 
leads to UBSAN warning and then oops:

[154316.118423] ================================================================================
[154316.118508] UBSAN: Undefined behaviour in drivers/scsi/scsi_lib.c:2328:27
[154316.118566] member access within null pointer of type 'struct Scsi_Host'
[154316.118631] CPU: 2 PID: 14530 Comm: reboot Tainted: G        W        4.15.0-dirty #89
[154316.118701] Hardware name: Hewlett Packard HP NetServer/HP System Board, BIOS 4.06.46 PW 06/25/2003
[154316.118774] Call Trace:
[154316.118848]  dump_stack+0x48/0x65
[154316.118916]  ubsan_epilogue+0xe/0x40
[154316.118976]  __ubsan_handle_type_mismatch+0xfb/0x180
[154316.119043]  scsi_block_requests+0x20/0x30
[154316.119135]  aac_shutdown+0x18/0x40 [aacraid]
[154316.119196]  pci_device_shutdown+0x33/0x50
[154316.119269]  device_shutdown+0x18a/0x390
[...]
[154316.123435] BUG: unable to handle kernel NULL pointer dereference at 000000f4
[154316.123515] IP: scsi_block_requests+0xa/0x30

This is because aac_shutdown() does

        struct Scsi_Host *shost = pci_get_drvdata(dev);
        scsi_block_requests(shost);

and that assumes shost has been assigned with pci_set_drvdata().

However, pci_set_drvdata(pdev, shost) is done in aac_probe_one() far 
after bailing out with error from calling the init function 
((*aac_drivers[index].init)(aac)), and when the init function fails, no 
error is returned from aac_probe_one() so PCI layer assumes there is 
driver attached, and tries to shut it down later.

Fix it by returning error from aac_probe_one() when card-specific init 
function fails.

This fixes reboot on my HP NetRAID-4M with dead battery.

Signed-off-by: Meelis Roos <mroos@linux.ee>

diff --git a/drivers/scsi/aacraid/linit.c b/drivers/scsi/aacraid/linit.c
index d55332de08f9..01c171e440bd 100644
--- a/drivers/scsi/aacraid/linit.c
+++ b/drivers/scsi/aacraid/linit.c
@@ -1693,8 +1693,10 @@ static int aac_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
 	 *	Map in the registers from the adapter.
 	 */
 	aac->base_size = AAC_MIN_FOOTPRINT_SIZE;
-	if ((*aac_drivers[index].init)(aac))
+	if ((*aac_drivers[index].init)(aac)) {
+		error = -ENODEV;
 		goto out_unmap;
+	}
 
 	if (aac->sync_mode) {
 		if (aac_sync_mode)

-- 
Meelis Roos (mroos@linux.ee)

RE: [PATCH] aacraid: fix shutdown crash when init fails

[Dave Carroll]

> -----Original Message-----
> From: mroos@math.ut.ee [mailto:mroos@math.ut.ee] On Behalf Of Meelis
> Roos
> Sent: Thursday, February 08, 2018 11:58 PM
> To: linux-scsi@vger.kernel.org; dl-esc-Aacraid Linux Driver
> <aacraid@microsemi.com>
> Subject: [PATCH] aacraid: fix shutdown crash when init fails
> 
> 
> When aacraid init fails with "AAC0: adapter self-test failed.", shutdown leads to
> UBSAN warning and then oops:
> 
> [154316.118423]
> =================================================================
> ===============
> [154316.118508] UBSAN: Undefined behaviour in drivers/scsi/scsi_lib.c:2328:27
> [154316.118566] member access within null pointer of type 'struct Scsi_Host'
> [154316.118631] CPU: 2 PID: 14530 Comm: reboot Tainted: G        W        4.15.0-
> dirty #89
> [154316.118701] Hardware name: Hewlett Packard HP NetServer/HP System
> Board, BIOS 4.06.46 PW 06/25/2003 [154316.118774] Call Trace:
> [154316.118848]  dump_stack+0x48/0x65
> [154316.118916]  ubsan_epilogue+0xe/0x40 [154316.118976]
> __ubsan_handle_type_mismatch+0xfb/0x180
> [154316.119043]  scsi_block_requests+0x20/0x30 [154316.119135]
> aac_shutdown+0x18/0x40 [aacraid] [154316.119196]
> pci_device_shutdown+0x33/0x50 [154316.119269]
> device_shutdown+0x18a/0x390 [...] [154316.123435] BUG: unable to handle
> kernel NULL pointer dereference at 000000f4 [154316.123515] IP:
> scsi_block_requests+0xa/0x30
> 
> This is because aac_shutdown() does
> 
>         struct Scsi_Host *shost = pci_get_drvdata(dev);
>         scsi_block_requests(shost);
> 
> and that assumes shost has been assigned with pci_set_drvdata().
> 
> However, pci_set_drvdata(pdev, shost) is done in aac_probe_one() far after
> bailing out with error from calling the init function
> ((*aac_drivers[index].init)(aac)), and when the init function fails, no error is
> returned from aac_probe_one() so PCI layer assumes there is driver attached,
> and tries to shut it down later.
> 
> Fix it by returning error from aac_probe_one() when card-specific init function
> fails.
> 
> This fixes reboot on my HP NetRAID-4M with dead battery.
> 
> Signed-off-by: Meelis Roos <mroos@linux.ee>

Reviewed-by: Dave Carroll <david.carroll@microsemi.com>

Re: [PATCH] aacraid: fix shutdown crash when init fails

[Martin K. Petersen]

Meelis,

> When aacraid init fails with "AAC0: adapter self-test failed.",
> shutdown leads to UBSAN warning and then oops:

Applied to 4.16/scsi-fixes. Thank you!

-- 
Martin K. Petersen	Oracle Linux Engineering