In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Add NULL check for clk_mgr and clk_mgr->funcs in dcn30_init_hw
This commit addresses a potential null pointer dereference issue in the
`dcn30_init_hw` function. The issue could occur when `dc->clk_mgr` or
`dc->clk_mgr->funcs` is null.
The fix adds a check to ensure `dc->clk_mgr` and `dc->clk_mgr->funcs` is
not null before accessing its functions. This prevents a potential null
pointer dereference.
Reported by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn30/dcn30_hwseq.c:789 dcn30_init_hw() error: we previously assumed 'dc->clk_mgr' could be null (see line 628)
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Check phantom_stream before it is used
dcn32_enable_phantom_stream can return null, so returned value
must be checked before used.
This fixes 1 NULL_RETURNS issue reported by Coverity.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Check null-initialized variables
[WHAT & HOW]
drr_timing and subvp_pipe are initialized to null and they are not
always assigned new values. It is necessary to check for null before
dereferencing.
This fixes 2 FORWARD_NULL issues reported by Coverity.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Initialize denominators' default to 1
[WHAT & HOW]
Variables used as denominators and maybe not assigned to other values,
should not be 0. Change their default to 1 so they are never 0.
This fixes 10 DIVIDE_BY_ZERO issues reported by Coverity.
In the Linux kernel, the following vulnerability has been resolved:
drm/msm/adreno: Assign msm_gpu->pdev earlier to avoid nullptrs
There are some cases, such as the one uncovered by Commit 46d4efcccc68
("drm/msm/a6xx: Avoid a nullptr dereference when speedbin setting fails")
where
msm_gpu_cleanup() : platform_set_drvdata(gpu->pdev, NULL);
is called on gpu->pdev == NULL, as the GPU device has not been fully
initialized yet.
Turns out that there's more than just the aforementioned path that
causes this to happen (e.g. the case when there's speedbin data in the
catalog, but opp-supported-hw is missing in DT).
Assigning msm_gpu->pdev earlier seems like the least painful solution
to this, therefore do so.
Patchwork: https://patchwork.freedesktop.org/patch/602742/
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: add list empty check to avoid null pointer issue
Add list empty check to avoid null pointer issues in some corner cases.
- list_for_each_entry_safe()
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix a sdiv overflow issue
Zac Ecob reported a problem where a bpf program may cause kernel crash due
to the following error:
Oops: divide error: 0000 [#1] PREEMPT SMP KASAN PTI
The failure is due to the below signed divide:
LLONG_MIN/-1 where LLONG_MIN equals to -9,223,372,036,854,775,808.
LLONG_MIN/-1 is supposed to give a positive number 9,223,372,036,854,775,808,
but it is impossible since for 64-bit system, the maximum positive
number is 9,223,372,036,854,775,807. On x86_64, LLONG_MIN/-1 will
cause a kernel exception. On arm64, the result for LLONG_MIN/-1 is
LLONG_MIN.
Further investigation found all the following sdiv/smod cases may trigger
an exception when bpf program is running on x86_64 platform:
- LLONG_MIN/-1 for 64bit operation
- INT_MIN/-1 for 32bit operation
- LLONG_MIN%-1 for 64bit operation
- INT_MIN%-1 for 32bit operation
where -1 can be an immediate or in a register.
On arm64, there are no exceptions:
- LLONG_MIN/-1 = LLONG_MIN
- INT_MIN/-1 = INT_MIN
- LLONG_MIN%-1 = 0
- INT_MIN%-1 = 0
where -1 can be an immediate or in a register.
Insn patching is needed to handle the above cases and the patched codes
produced results aligned with above arm64 result. The below are pseudo
codes to handle sdiv/smod exceptions including both divisor -1 and divisor 0
and the divisor is stored in a register.
sdiv:
tmp = rX
tmp += 1 /* [-1, 0] -> [0, 1]
if tmp >(unsigned) 1 goto L2
if tmp == 0 goto L1
rY = 0
L1:
rY = -rY;
goto L3
L2:
rY /= rX
L3:
smod:
tmp = rX
tmp += 1 /* [-1, 0] -> [0, 1]
if tmp >(unsigned) 1 goto L1
if tmp == 1 (is64 ? goto L2 : goto L3)
rY = 0;
goto L2
L1:
rY %= rX
L2:
goto L4 // only when !is64
L3:
wY = wY // only when !is64
L4:
[1] https://lore.kernel.org/bpf/tPJLTEh7S_DxFEqAI2Ji5MBSoZVg7_G-Py2iaZpAaWtM961fFTWtsnlzwvTbzBzaUzwQAoNATXKUlt0LZOFgnDcIyKCswAnAGdUF3LBrhGQ=@protonmail.com/
In the Linux kernel, the following vulnerability has been resolved:
scsi: lpfc: Validate hdwq pointers before dereferencing in reset/errata paths
When the HBA is undergoing a reset or is handling an errata event, NULL ptr
dereference crashes may occur in routines such as
lpfc_sli_flush_io_rings(), lpfc_dev_loss_tmo_callbk(), or
lpfc_abort_handler().
Add NULL ptr checks before dereferencing hdwq pointers that may have been
freed due to operations colliding with a reset or errata event handler.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Check stream_status before it is used
[WHAT & HOW]
dc_state_get_stream_status can return null, and therefore null must be
checked before stream_status is used.
This fixes 1 NULL_RETURNS issue reported by Coverity.
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix helper writes to read-only maps
Lonial found an issue that despite user- and BPF-side frozen BPF map
(like in case of .rodata), it was still possible to write into it from
a BPF program side through specific helpers having ARG_PTR_TO_{LONG,INT}
as arguments.
In check_func_arg() when the argument is as mentioned, the meta->raw_mode
is never set. Later, check_helper_mem_access(), under the case of
PTR_TO_MAP_VALUE as register base type, it assumes BPF_READ for the
subsequent call to check_map_access_type() and given the BPF map is
read-only it succeeds.
The helpers really need to be annotated as ARG_PTR_TO_{LONG,INT} | MEM_UNINIT
when results are written into them as opposed to read out of them. The
latter indicates that it's okay to pass a pointer to uninitialized memory
as the memory is written to anyway.
However, ARG_PTR_TO_{LONG,INT} is a special case of ARG_PTR_TO_FIXED_SIZE_MEM
just with additional alignment requirement. So it is better to just get
rid of the ARG_PTR_TO_{LONG,INT} special cases altogether and reuse the
fixed size memory types. For this, add MEM_ALIGNED to additionally ensure
alignment given these helpers write directly into the args via *<ptr> = val.
The .arg*_size has been initialized reflecting the actual sizeof(*<ptr>).
MEM_ALIGNED can only be used in combination with MEM_FIXED_SIZE annotated
argument types, since in !MEM_FIXED_SIZE cases the verifier does not know
the buffer size a priori and therefore cannot blindly write *<ptr> = val.