From 2dedcf414bb01b8d966eb445db1d181d92304fb2 Mon Sep 17 00:00:00 2001 From: Guchun Chen Date: Mon, 24 Jul 2023 10:42:29 +0800 Subject: [PATCH] drm/ttm: check null pointer before accessing when swapping MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Add a check to avoid null pointer dereference as below: [ 90.002283] general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI [ 90.002292] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] [ 90.002346] ? exc_general_protection+0x159/0x240 [ 90.002352] ? asm_exc_general_protection+0x26/0x30 [ 90.002357] ? ttm_bo_evict_swapout_allowable+0x322/0x5e0 [ttm] [ 90.002365] ? ttm_bo_evict_swapout_allowable+0x42e/0x5e0 [ttm] [ 90.002373] ttm_bo_swapout+0x134/0x7f0 [ttm] [ 90.002383] ? __pfx_ttm_bo_swapout+0x10/0x10 [ttm] [ 90.002391] ? lock_acquire+0x44d/0x4f0 [ 90.002398] ? ttm_device_swapout+0xa5/0x260 [ttm] [ 90.002412] ? lock_acquired+0x355/0xa00 [ 90.002416] ? do_raw_spin_trylock+0xb6/0x190 [ 90.002421] ? __pfx_lock_acquired+0x10/0x10 [ 90.002426] ? ttm_global_swapout+0x25/0x210 [ttm] [ 90.002442] ttm_device_swapout+0x198/0x260 [ttm] [ 90.002456] ? __pfx_ttm_device_swapout+0x10/0x10 [ttm] [ 90.002472] ttm_global_swapout+0x75/0x210 [ttm] [ 90.002486] ttm_tt_populate+0x187/0x3f0 [ttm] [ 90.002501] ttm_bo_handle_move_mem+0x437/0x590 [ttm] [ 90.002517] ttm_bo_validate+0x275/0x430 [ttm] [ 90.002530] ? __pfx_ttm_bo_validate+0x10/0x10 [ttm] [ 90.002544] ? kasan_save_stack+0x33/0x60 [ 90.002550] ? kasan_set_track+0x25/0x30 [ 90.002554] ? __kasan_kmalloc+0x8f/0xa0 [ 90.002558] ? amdgpu_gtt_mgr_new+0x81/0x420 [amdgpu] [ 90.003023] ? ttm_resource_alloc+0xf6/0x220 [ttm] [ 90.003038] amdgpu_bo_pin_restricted+0x2dd/0x8b0 [amdgpu] [ 90.003210] ? __x64_sys_ioctl+0x131/0x1a0 [ 90.003210] ? do_syscall_64+0x60/0x90 Fixes: a2848d08742c ("drm/ttm: never consider pinned BOs for eviction&swap") Tested-by: Mikhail Gavrilov Signed-off-by: Guchun Chen Reviewed-by: Alex Deucher Reviewed-by: Christian König Cc: stable@vger.kernel.org Link: https://patchwork.freedesktop.org/patch/msgid/20230724024229.1118444-1-guchun.chen@amd.com Signed-off-by: Christian König --- drivers/gpu/drm/ttm/ttm_bo.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index 7139a522b2f3..54e3083076b7 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -519,7 +519,8 @@ static bool ttm_bo_evict_swapout_allowable(struct ttm_buffer_object *bo, if (bo->pin_count) { *locked = false; - *busy = false; + if (busy) + *busy = false; return false; } -- 2.34.1