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* [PATCH] crypto: ccp - Always pass in an error pointer to __sev_platform_shutdown_locked()
@ 2025-09-06 12:21 Borislav Petkov
  2025-09-06 21:15 ` Kalra, Ashish
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Borislav Petkov @ 2025-09-06 12:21 UTC (permalink / raw)
  To: Ashish Kalra
  Cc: Tom Lendacky, Herbert Xu, linux-crypto, LKML,
	Borislav Petkov (AMD), stable

From: "Borislav Petkov (AMD)" <bp@alien8.de>

When

  9770b428b1a2 ("crypto: ccp - Move dev_info/err messages for SEV/SNP init and shutdown")

moved the error messages dumping so that they don't need to be issued by
the callers, it missed the case where __sev_firmware_shutdown() calls
__sev_platform_shutdown_locked() with a NULL argument which leads to
a NULL ptr deref on the shutdown path, during suspend to disk:

  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 0 P4D 0
  Oops: Oops: 0000 [#1] SMP NOPTI
  CPU: 0 UID: 0 PID: 983 Comm: hib.sh Not tainted 6.17.0-rc4+ #1 PREEMPT(voluntary)
  Hardware name: Supermicro Super Server/H12SSL-i, BIOS 2.5 09/08/2022
  RIP: 0010:__sev_platform_shutdown_locked.cold+0x0/0x21 [ccp]

That rIP is:

  00000000000006fd <__sev_platform_shutdown_locked.cold>:
   6fd:   8b 13                   mov    (%rbx),%edx
   6ff:   48 8b 7d 00             mov    0x0(%rbp),%rdi
   703:   89 c1                   mov    %eax,%ecx

  Code: 74 05 31 ff 41 89 3f 49 8b 3e 89 ea 48 c7 c6 a0 8e 54 a0 41 bf 92 ff ff ff e8 e5 2e 09 e1 c6 05 2a d4 38 00 01 e9 26 af ff ff <8b> 13 48 8b 7d 00 89 c1 48 c7 c6 18 90 54 a0 89 44 24 04 e8 c1 2e
  RSP: 0018:ffffc90005467d00 EFLAGS: 00010282
  RAX: 00000000ffffff92 RBX: 0000000000000000 RCX: 0000000000000000
  			     ^^^^^^^^^^^^^^^^
and %rbx is nice and clean.

  Call Trace:
   <TASK>
   __sev_firmware_shutdown.isra.0
   sev_dev_destroy
   psp_dev_destroy
   sp_destroy
   pci_device_shutdown
   device_shutdown
   kernel_power_off
   hibernate.cold
   state_store
   kernfs_fop_write_iter
   vfs_write
   ksys_write
   do_syscall_64
   entry_SYSCALL_64_after_hwframe

Pass in a pointer to the function-local error var in the caller.

With that addressed, suspending the ccp shows the error properly at
least:

  ccp 0000:47:00.1: sev command 0x2 timed out, disabling PSP
  ccp 0000:47:00.1: SEV: failed to SHUTDOWN error 0x0, rc -110
  SEV-SNP: Leaking PFN range 0x146800-0x146a00
  SEV-SNP: PFN 0x146800 unassigned, dumping non-zero entries in 2M PFN region: [0x146800 - 0x146a00]
  ...
  ccp 0000:47:00.1: SEV-SNP firmware shutdown failed, rc -16, error 0x0
  ACPI: PM: Preparing to enter system sleep state S5
  kvm: exiting hardware virtualization
  reboot: Power down

Btw, this driver is crying to be cleaned up to pass in a proper I/O
struct which can be used to store information between the different
functions, otherwise stuff like that will happen in the future again.

Fixes: 9770b428b1a2 ("crypto: ccp - Move dev_info/err messages for SEV/SNP init and shutdown")
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
---
 drivers/crypto/ccp/sev-dev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index e058ba027792..9f5ccc1720cb 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -2430,7 +2430,7 @@ static void __sev_firmware_shutdown(struct sev_device *sev, bool panic)
 {
 	int error;
 
-	__sev_platform_shutdown_locked(NULL);
+	__sev_platform_shutdown_locked(&error);
 
 	if (sev_es_tmr) {
 		/*
-- 
2.51.0


^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2025-09-13  4:31 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-09-06 12:21 [PATCH] crypto: ccp - Always pass in an error pointer to __sev_platform_shutdown_locked() Borislav Petkov
2025-09-06 21:15 ` Kalra, Ashish
2025-09-08 17:07 ` Tom Lendacky
2025-09-13  4:31 ` Herbert Xu

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