From bd68a1404b6fa2e7e9957b38ba22616faba43e75 Mon Sep 17 00:00:00 2001 From: Asad Kamal Date: Fri, 21 Nov 2025 00:46:23 +0800 Subject: [PATCH] drm/amdgpu/ras: Move ras data alloc before bad page check In the rare event if eeprom has only invalid address entries, allocation is skipped, this causes following NULL pointer issue [ 547.103445] BUG: kernel NULL pointer dereference, address: 0000000000000010 [ 547.118897] #PF: supervisor read access in kernel mode [ 547.130292] #PF: error_code(0x0000) - not-present page [ 547.141689] PGD 124757067 P4D 0 [ 547.148842] Oops: 0000 [#1] PREEMPT SMP NOPTI [ 547.158504] CPU: 49 PID: 8167 Comm: cat Tainted: G OE 6.8.0-38-generic #38-Ubuntu [ 547.177998] Hardware name: Supermicro AS -8126GS-TNMR/H14DSG-OD, BIOS 1.7 09/12/2025 [ 547.195178] RIP: 0010:amdgpu_ras_sysfs_badpages_read+0x2f2/0x5d0 [amdgpu] [ 547.210375] Code: e8 63 78 82 c0 45 31 d2 45 3b 75 08 48 8b 45 a0 73 44 44 89 f1 48 8b 7d 88 48 89 ca 48 c1 e2 05 48 29 ca 49 8b 4d 00 48 01 d1 <48> 83 79 10 00 74 17 49 63 f2 48 8b 49 08 41 83 c2 01 48 8d 34 76 [ 547.252045] RSP: 0018:ffa0000067287ac0 EFLAGS: 00010246 [ 547.263636] RAX: ff11000167c28130 RBX: ff11000127600000 RCX: 0000000000000000 [ 547.279467] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ff11000125b1c800 [ 547.295298] RBP: ffa0000067287b50 R08: 0000000000000000 R09: 0000000000000000 [ 547.311129] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 547.326959] R13: ff11000217b1de00 R14: 0000000000000000 R15: 0000000000000092 [ 547.342790] FS: 0000746e59d14740(0000) GS:ff11017dfda80000(0000) knlGS:0000000000000000 [ 547.360744] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 547.373489] CR2: 0000000000000010 CR3: 000000019585e001 CR4: 0000000000f71ef0 [ 547.389321] PKRU: 55555554 [ 547.395316] Call Trace: [ 547.400737] [ 547.405386] ? show_regs+0x6d/0x80 [ 547.412929] ? __die+0x24/0x80 [ 547.419697] ? page_fault_oops+0x99/0x1b0 [ 547.428588] ? do_user_addr_fault+0x2ee/0x6b0 [ 547.438249] ? exc_page_fault+0x83/0x1b0 [ 547.446949] ? asm_exc_page_fault+0x27/0x30 [ 547.456225] ? amdgpu_ras_sysfs_badpages_read+0x2f2/0x5d0 [amdgpu] [ 547.470040] ? mas_wr_modify+0xcd/0x140 [ 547.478548] sysfs_kf_bin_read+0x63/0xb0 [ 547.487248] kernfs_file_read_iter+0xa1/0x190 [ 547.496909] kernfs_fop_read_iter+0x25/0x40 [ 547.506182] vfs_read+0x255/0x390 This also result in space left assigned to negative values. Moving data alloc call before bad page check resolves both the issue. Signed-off-by: Asad Kamal Suggested-by: Lijo Lazar Reviewed-by: Hawking Zhang Reviewed-by: Lijo Lazar Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c index d79b41ce2124..3d51a3c8852a 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c @@ -3076,6 +3076,11 @@ static int __amdgpu_ras_restore_bad_pages(struct amdgpu_device *adev, struct ras_err_handler_data *data = con->eh_data; for (j = 0; j < count; j++) { + if (!data->space_left && + amdgpu_ras_realloc_eh_data_space(adev, data, 256)) { + return -ENOMEM; + } + if (amdgpu_ras_check_bad_page_unlock(con, bps[j].retired_page << AMDGPU_GPU_PAGE_SHIFT)) { data->count++; @@ -3083,11 +3088,6 @@ static int __amdgpu_ras_restore_bad_pages(struct amdgpu_device *adev, continue; } - if (!data->space_left && - amdgpu_ras_realloc_eh_data_space(adev, data, 256)) { - return -ENOMEM; - } - amdgpu_ras_reserve_page(adev, bps[j].retired_page); memcpy(&data->bps[data->count], &(bps[j]), -- 2.47.3