FAILED: patch "[PATCH] scsi: ufs: Fix NULL pointer dereference in" failed to apply to 4.4-stable tree

The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From 7c7cfdcf7f1777c7376fc9a239980de04b6b5ea1 Mon Sep 17 00:00:00 2001

From: Adrian Hunter <[email protected]>
Date: Wed, 14 Aug 2019 15:59:50 +0300
Subject: [PATCH] scsi: ufs: Fix NULL pointer dereference in
ufshcd_config_vreg_hpm()

Fix the following BUG:

  [ 187.065689] BUG: kernel NULL pointer dereference, address: 000000000000001c
  [ 187.065790] RIP: 0010:ufshcd_vreg_set_hpm+0x3c/0x110 [ufshcd_core]
  [ 187.065938] Call Trace:
  [ 187.065959] ufshcd_resume+0x72/0x290 [ufshcd_core]
  [ 187.065980] ufshcd_system_resume+0x54/0x140 [ufshcd_core]
  [ 187.065993] ? pci_pm_restore+0xb0/0xb0
  [ 187.066005] ufshcd_pci_resume+0x15/0x20 [ufshcd_pci]
  [ 187.066017] pci_pm_thaw+0x4c/0x90
  [ 187.066030] dpm_run_callback+0x5b/0x150
  [ 187.066043] device_resume+0x11b/0x220

Voltage regulators are optional, so functions must check they exist before dereferencing.

Note this issue is hidden if CONFIG_REGULATORS is not set, because the offending code is optimised away.

Notes for stable:

The issue first appears in commit 57d104c153d3 ("ufs: add UFS power management support") but is inadvertently fixed in commit 60f0187031c0 ("scsi: ufs: disable vccq if it's not needed by UFS device") which in turn was reverted by commit 730679817d83 ("Revert "scsi: ufs: disable vccq if it's not needed by UFS device""). So fix applies v3.18 to v4.5 and v5.1+

Fixes 57d104c153d3 ("ufs: add UFS power management support")

Fixes 730679817d83 ("Revert "scsi: ufs: disable vccq if it's not needed by UFS device"")

Cc [email protected]

Signed-off-by Adrian Hunter <[email protected]>

Signed-off-by Martin K. Petersen <[email protected]>

drivers/scsi/ufs/ufshcd.c +3 -0

index e274053109d0..029da74bb2f5 100644
@@ -7062,6 +7062,9 @@ static inline int ufshcd_config_vreg_lpm(struct ufs_hba *hba,
 static inline int ufshcd_config_vreg_hpm(struct ufs_hba *hba,
 					 struct ufs_vreg *vreg)
 {
+	if (!vreg)
+		return 0;
+
 	return ufshcd_config_vreg_load(hba->dev, vreg, vreg->max_uA);
 }
 

Seems to works for me:

$ git log | head -5
commit 5e9f4d704f8698b6d655afa7e9fac3509da253bc
Author: Greg Kroah-Hartman <[email protected]>
Date:   Sun Aug 25 10:53:06 2019 +0200

    Linux 4.4.190

$ git cherry-pick 7c7cfdcf7f1777c7376fc9a239980de04b6b5ea1
warning: inexact rename detection was skipped due to too many files.
warning: you may want to set your merge.renamelimit variable to at least 22729 and retry the command.
[linux-4.4.y 9558a3c05149] scsi: ufs: Fix NULL pointer dereference in ufshcd_config_vreg_hpm()
 Date: Wed Aug 14 15:59:50 2019 +0300
 1 file changed, 3 insertions(+)

$ git log | head -5
commit 9558a3c05149ded7136c24325dd3952276fcdaaa
Author: Adrian Hunter <[email protected]>
Date:   Wed Aug 14 15:59:50 2019 +0300

scsi: ufs: Fix NULL pointer dereference in ufshcd_config_vreg_hpm()

Quoted 21 lines · Adrian Hunter

Seems to works for me:

$ git log | head -5
commit 5e9f4d704f8698b6d655afa7e9fac3509da253bc
Author: Greg Kroah-Hartman <[email protected]>
Date:   Sun Aug 25 10:53:06 2019 +0200

    Linux 4.4.190

$ git cherry-pick 7c7cfdcf7f1777c7376fc9a239980de04b6b5ea1
warning: inexact rename detection was skipped due to too many files.
warning: you may want to set your merge.renamelimit variable to at least 22729 and retry the command.
[linux-4.4.y 9558a3c05149] scsi: ufs: Fix NULL pointer dereference in ufshcd_config_vreg_hpm()
 Date: Wed Aug 14 15:59:50 2019 +0300
 1 file changed, 3 insertions(+)

$ git log | head -5
commit 9558a3c05149ded7136c24325dd3952276fcdaaa
Author: Adrian Hunter <[email protected]>
Date:   Wed Aug 14 15:59:50 2019 +0300

Quoted 2 lines

scsi: ufs: Fix NULL pointer dereference in ufshcd_config_vreg_hpm()

I do not use cherry-pick, I use quilt. Can you please provide the resulting patch that you created here, after you verify that it really is correct (see the git warning...)

Quoted 27 lines · Greg KH

Quoted 25 lines · Adrian Hunter

Seems to works for me:

$ git log | head -5
commit 5e9f4d704f8698b6d655afa7e9fac3509da253bc
Author: Greg Kroah-Hartman <[email protected]>
Date:   Sun Aug 25 10:53:06 2019 +0200

    Linux 4.4.190

$ git cherry-pick 7c7cfdcf7f1777c7376fc9a239980de04b6b5ea1
warning: inexact rename detection was skipped due to too many files.
warning: you may want to set your merge.renamelimit variable to at least
22729 and retry the command.
[linux-4.4.y 9558a3c05149] scsi: ufs: Fix NULL pointer dereference in
ufshcd_config_vreg_hpm()
 Date: Wed Aug 14 15:59:50 2019 +0300
 1 file changed, 3 insertions(+)

$ git log | head -5
commit 9558a3c05149ded7136c24325dd3952276fcdaaa
Author: Adrian Hunter <[email protected]>
Date:   Wed Aug 14 15:59:50 2019 +0300

    scsi: ufs: Fix NULL pointer dereference in ufshcd_config_vreg_hpm()

Quoted 3 lines

I do not use cherry-pick, I use quilt.  Can you please provide the resulting patch that you created here, after you verify that it really is correct (see the git warning...)

Looks like the patched function moved around more than quilt liked. I've confirmed that what git does is correct and queued it for 4.4. It is not needed for 4.9, 4.14 and 4.19.