From 31ab27b14daaa75541a415c6794d6f3567fea44a Mon Sep 17 00:00:00 2001 From: Dave Airlie Date: Mon, 23 May 2022 10:24:18 +1000 Subject: [PATCH] drm/amdgpu/cs: make commands with 0 chunks illegal behaviour. Submitting a cs with 0 chunks, causes an oops later, found trying to execute the wrong userspace driver. MESA_LOADER_DRIVER_OVERRIDE=v3d glxinfo [172536.665184] BUG: kernel NULL pointer dereference, address: 00000000000001d8 [172536.665188] #PF: supervisor read access in kernel mode [172536.665189] #PF: error_code(0x0000) - not-present page [172536.665191] PGD 6712a0067 P4D 6712a0067 PUD 5af9ff067 PMD 0 [172536.665195] Oops: 0000 [#1] SMP NOPTI [172536.665197] CPU: 7 PID: 2769838 Comm: glxinfo Tainted: P O 5.10.81 #1-NixOS [172536.665199] Hardware name: To be filled by O.E.M. To be filled by O.E.M./CROSSHAIR V FORMULA-Z, BIOS 2201 03/23/2015 [172536.665272] RIP: 0010:amdgpu_cs_ioctl+0x96/0x1ce0 [amdgpu] [172536.665274] Code: 75 18 00 00 4c 8b b2 88 00 00 00 8b 46 08 48 89 54 24 68 49 89 f7 4c 89 5c 24 60 31 d2 4c 89 74 24 30 85 c0 0f 85 c0 01 00 00 <48> 83 ba d8 01 00 00 00 48 8b b4 24 90 00 00 00 74 16 48 8b 46 10 [172536.665276] RSP: 0018:ffffb47c0e81bbe0 EFLAGS: 00010246 [172536.665277] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [172536.665278] RDX: 0000000000000000 RSI: ffffb47c0e81be28 RDI: ffffb47c0e81bd68 [172536.665279] RBP: ffff936524080010 R08: 0000000000000000 R09: ffffb47c0e81be38 [172536.665281] R10: ffff936524080010 R11: ffff936524080000 R12: ffffb47c0e81bc40 [172536.665282] R13: ffffb47c0e81be28 R14: ffff9367bc410000 R15: ffffb47c0e81be28 [172536.665283] FS: 00007fe35e05d740(0000) GS:ffff936c1edc0000(0000) knlGS:0000000000000000 [172536.665284] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [172536.665286] CR2: 00000000000001d8 CR3: 0000000532e46000 CR4: 00000000000406e0 [172536.665287] Call Trace: [172536.665322] ? amdgpu_cs_find_mapping+0x110/0x110 [amdgpu] [172536.665332] drm_ioctl_kernel+0xaa/0xf0 [drm] [172536.665338] drm_ioctl+0x201/0x3b0 [drm] [172536.665369] ? amdgpu_cs_find_mapping+0x110/0x110 [amdgpu] [172536.665372] ? selinux_file_ioctl+0x135/0x230 [172536.665399] amdgpu_drm_ioctl+0x49/0x80 [amdgpu] [172536.665403] __x64_sys_ioctl+0x83/0xb0 [172536.665406] do_syscall_64+0x33/0x40 [172536.665409] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/2018 Signed-off-by: Dave Airlie Cc: stable@vger.kernel.org Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c index 84caab5e4d22..b28af04b0c3e 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c @@ -116,7 +116,7 @@ static int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, union drm_amdgpu_cs int ret; if (cs->in.num_chunks == 0) - return 0; + return -EINVAL; chunk_array = kvmalloc_array(cs->in.num_chunks, sizeof(uint64_t), GFP_KERNEL); if (!chunk_array) -- 2.20.1