On 8/25/2022 5:16 PM, Russell, Kent wrote:
[AMD Official Use Only - General]
Friendly ping
Wonder how it goes any further when m is NULL. It should do shortcut
evaluation and return NOTIFY_DONE, right? Or is this for better readability?
Thanks,
Lijo
Kent
-----Original Message-----
From: Russell, Kent <Kent.Russell@xxxxxxx>
Sent: Monday, August 15, 2022 11:31 AM
To: amd-gfx@xxxxxxxxxxxxxxxxxxxxx
Cc: Ghannam, Yazen <Yazen.Ghannam@xxxxxxx>; Russell, Kent <Kent.Russell@xxxxxxx>
Subject: [PATCH] drm/amdgpu: Handle potential NULL pointer dereference
If m is NULL, we will end up referencing a NULL pointer in the subsequent m elements like extcpu, bank and status. Pull the NULL check out and do it first before referencing m's elements.
Signed-off-by: Kent Russell <kent.russell@xxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
index ab9ba5a9c33d..028495fdfa62 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
@@ -2838,12 +2838,15 @@ static int amdgpu_bad_page_notifier(struct notifier_block *nb,
struct eeprom_table_record err_rec;
uint64_t retired_page;
+ if (!m)
+ return NOTIFY_DONE;
+
/*
* If the error was generated in UMC_V2, which belongs to GPU UMCs,
* and error occurred in DramECC (Extended error code = 0) then only
* process the error, else bail out.
*/
- if (!m || !((smca_get_bank_type(m->extcpu, m->bank) == SMCA_UMC_V2) &&
+ if (!((smca_get_bank_type(m->extcpu, m->bank) == SMCA_UMC_V2) &&
(XEC(m->status, 0x3f) == 0x0)))
return NOTIFY_DONE;
--
2.25.1
