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| author | Muhammad Bilal <meatuni001@gmail.com> | 2026-07-28 17:54:55 +0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-09-01 12:15:16 +0200 |
| commit | ff917923f4fb9c83717ba135ee47d7e4c1567bb7 (patch) | |
| tree | c38fd8fcf58e1937b17fdbc6518b6f8b797fc15a /Documentation/gpu/amdgpu/debugging.rst | |
| download | linux-stable-ff917923f4fb9c83717ba135ee47d7e4c1567bb7.tar.gz linux-stable-ff917923f4fb9c83717ba135ee47d7e4c1567bb7.zip | |
staging: rtl8723bs: fix OOB read in rtw_action_frame_parse()grafted
rtw_action_frame_parse() takes a frame_len parameter but never
actually checks it before indexing into the frame body:
const u8 *frame_body = frame + sizeof(struct ieee80211_hdr_3addr);
...
c = frame_body[0];
...
a = frame_body[1];
frame_body already points 24 bytes (sizeof(struct
ieee80211_hdr_3addr)) into frame, so reading frame_body[0] and
frame_body[1] requires frame_len >= 26. A management action frame
shorter than that (e.g. exactly 24 bytes, the minimum a malicious
peer can send) causes a 1-2 byte out-of-bounds read.
This is reachable from rtw_cfg80211_monitor_if_xmit_entry() and
cfg80211_rtw_mgmt_tx() in ioctl_cfg80211.c, both of which pass
attacker/user-influenced frame buffers and lengths straight through.
Add the missing length check before frame_body is dereferenced.
Fixes: 554c0a3abf216 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable@vger.kernel.org
Signed-off-by: Muhammad Bilal <meatuni001@gmail.com>
Link: https://patch.msgid.link/20260728125456.32359-3-meatuni001@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/gpu/amdgpu/debugging.rst')
| -rw-r--r-- | Documentation/gpu/amdgpu/debugging.rst | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/Documentation/gpu/amdgpu/debugging.rst b/Documentation/gpu/amdgpu/debugging.rst new file mode 100644 index 000000000..ac914d524 --- /dev/null +++ b/Documentation/gpu/amdgpu/debugging.rst @@ -0,0 +1,105 @@ +=============== + GPU Debugging +=============== + +General Debugging Options +========================= + +The DebugFS section provides documentation on a number files to aid in debugging +issues on the GPU. + + +GPUVM Debugging +=============== + +To aid in debugging GPU virtual memory related problems, the driver supports a +number of options module parameters: + +`vm_fault_stop` - If non-0, halt the GPU memory controller on a GPU page fault. + +`vm_update_mode` - If non-0, use the CPU to update GPU page tables rather than +the GPU. + + +Decoding a GPUVM Page Fault +=========================== + +If you see a GPU page fault in the kernel log, you can decode it to figure +out what is going wrong in your application. A page fault in your kernel +log may look something like this: + +:: + + [gfxhub0] no-retry page fault (src_id:0 ring:24 vmid:3 pasid:32777, for process glxinfo pid 2424 thread glxinfo:cs0 pid 2425) + in page starting at address 0x0000800102800000 from IH client 0x1b (UTCL2) + VM_L2_PROTECTION_FAULT_STATUS:0x00301030 + Faulty UTCL2 client ID: TCP (0x8) + MORE_FAULTS: 0x0 + WALKER_ERROR: 0x0 + PERMISSION_FAULTS: 0x3 + MAPPING_ERROR: 0x0 + RW: 0x0 + +First you have the memory hub, gfxhub and mmhub. gfxhub is the memory +hub used for graphics, compute, and sdma on some chips. mmhub is the +memory hub used for multi-media and sdma on some chips. + +Next you have the vmid and pasid. If the vmid is 0, this fault was likely +caused by the kernel driver or firmware. If the vmid is non-0, it is generally +a fault in a user application. The pasid is used to link a vmid to a system +process id. If the process is active when the fault happens, the process +information will be printed. + +The GPU virtual address that caused the fault comes next. + +The client ID indicates the GPU block that caused the fault. +Some common client IDs: + +- CB/DB: The color/depth backend of the graphics pipe +- CPF: Command Processor Frontend +- CPC: Command Processor Compute +- CPG: Command Processor Graphics +- TCP/SQC/SQG: Shaders +- SDMA: SDMA engines +- VCN: Video encode/decode engines +- JPEG: JPEG engines + +PERMISSION_FAULTS describe what faults were encountered: + +- bit 0: the PTE was not valid +- bit 1: the PTE read bit was not set +- bit 2: the PTE write bit was not set +- bit 3: the PTE execute bit was not set + +Finally, RW, indicates whether the access was a read (0) or a write (1). + +In the example above, a shader (cliend id = TCP) generated a read (RW = 0x0) to +an invalid page (PERMISSION_FAULTS = 0x3) at GPU virtual address +0x0000800102800000. The user can then inspect their shader code and resource +descriptor state to determine what caused the GPU page fault. + +UMR +=== + +`umr <https://gitlab.freedesktop.org/tomstdenis/umr>`_ is a general purpose +GPU debugging and diagnostics tool. Please see the umr +`documentation <https://umr.readthedocs.io/en/main/>`_ for more information +about its capabilities. + +Debugging backlight brightness +============================== +Default backlight brightness is intended to be set via the policy advertised +by the firmware. Firmware will often provide different defaults for AC or DC. +Furthermore, some userspace software will save backlight brightness during +the previous boot and attempt to restore it. + +Some firmware also has support for a feature called "Custom Backlight Curves" +where an input value for brightness is mapped along a linearly interpolated +curve of brightness values that better match display characteristics. + +In the event of problems happening with backlight, there is a trace event +that can be enabled at bootup to log every brightness change request. +This can help isolate where the problem is. To enable the trace event add +the following to the kernel command line: + + tp_printk trace_event=amdgpu_dm:amdgpu_dm_brightness:mod:amdgpu trace_buf_size=1M |
