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:
ext4: avoid use-after-free in ext4_ext_show_leaf()
In ext4_find_extent(), path may be freed by error or be reallocated, so
using a previously saved *ppath may have been freed and thus may trigger
use-after-free, as follows:
ext4_split_extent
path = *ppath;
ext4_split_extent_at(ppath)
path = ext4_find_extent(ppath)
ext4_split_extent_at(ppath)
// ext4_find_extent fails to free path
// but zeroout succeeds
ext4_ext_show_leaf(inode, path)
eh = path[depth].p_hdr
// path use-after-free !!!
Similar to ext4_split_extent_at(), we use *ppath directly as an input to
ext4_ext_show_leaf(). Fix a spelling error by the way.
Same problem in ext4_ext_handle_unwritten_extents(). Since 'path' is only
used in ext4_ext_show_leaf(), remove 'path' and use *ppath directly.
This issue is triggered only when EXT_DEBUG is defined and therefore does
not affect functionality.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/pm: ensure the fw_info is not null before using it
This resolves the dereference null return value warning
reported by Coverity.
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: Initialize get_bytes_per_element's default to 1
Variables, used as denominators and maybe not assigned to other values,
should not be 0. bytes_per_element_y & bytes_per_element_c are
initialized by get_bytes_per_element() which should never return 0.
This fixes 10 DIVIDE_BY_ZERO issues reported by Coverity.
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:
drm/amd/display: Fix index out of bounds in degamma hardware format translation
Fixes index out of bounds issue in
`cm_helper_translate_curve_to_degamma_hw_format` function. The issue
could occur when the index 'i' exceeds the number of transfer function
points (TRANSFER_FUNC_POINTS).
The fix adds a check to ensure 'i' is within bounds before accessing the
transfer function points. If 'i' is out of bounds the function returns
false to indicate an error.
Reported by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:594 cm_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.red' 1025 <= s32max
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:595 cm_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.green' 1025 <= s32max
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:596 cm_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.blue' 1025 <= s32max
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix index out of bounds in DCN30 degamma hardware format translation
This commit addresses a potential index out of bounds issue in the
`cm3_helper_translate_curve_to_degamma_hw_format` function in the DCN30
color management module. The issue could occur when the index 'i'
exceeds the number of transfer function points (TRANSFER_FUNC_POINTS).
The fix adds a check to ensure 'i' is within bounds before accessing the
transfer function points. If 'i' is out of bounds, the function returns
false to indicate an error.
Reported by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn30/dcn30_cm_common.c:338 cm3_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.red' 1025 <= s32max
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn30/dcn30_cm_common.c:339 cm3_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.green' 1025 <= s32max
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn30/dcn30_cm_common.c:340 cm3_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.blue' 1025 <= s32max