In the Linux kernel, the following vulnerability has been resolved:
PCI/P2PDMA: Fix p2pmem_alloc_mmap() warning condition
Commit b7e282378773 has already changed the initial page refcount of
p2pdma page from one to zero, however, in p2pmem_alloc_mmap() it uses
"VM_WARN_ON_ONCE_PAGE(!page_ref_count(page))" to assert the initial page
refcount should not be zero and the following will be reported when
CONFIG_DEBUG_VM is enabled:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x380400000
flags: 0x20000000002000(reserved|node=0|zone=4)
raw: 0020000000002000 ff1100015e3ab440 0000000000000000 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: VM_WARN_ON_ONCE_PAGE(!page_ref_count(page))
------------[ cut here ]------------
WARNING: CPU: 5 PID: 449 at drivers/pci/p2pdma.c:240 p2pmem_alloc_mmap+0x83a/0xa60
Fix by using "page_ref_count(page)" as the assertion condition.
In the Linux kernel, the following vulnerability has been resolved:
pinctrl: canaan: k230: Fix NULL pointer dereference when parsing devicetree
When probing the k230 pinctrl driver, the kernel triggers a NULL pointer
dereference. The crash trace showed:
[ 0.732084] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000068
[ 0.740737] ...
[ 0.776296] epc : k230_pinctrl_probe+0x1be/0x4fc
In k230_pinctrl_parse_functions(), we attempt to retrieve the device
pointer via info->pctl_dev->dev, but info->pctl_dev is only initialized
after k230_pinctrl_parse_dt() completes.
At the time of DT parsing, info->pctl_dev is still NULL, leading to
the invalid dereference of info->pctl_dev->dev.
Use the already available device pointer from platform_device
instead of accessing through uninitialized pctl_dev.
In the Linux kernel, the following vulnerability has been resolved:
power: supply: rt9455: Fix use-after-free in power_supply_changed()
Using the `devm_` variant for requesting IRQ _before_ the `devm_`
variant for allocating/registering the `power_supply` handle, means that
the `power_supply` handle will be deallocated/unregistered _before_ the
interrupt handler (since `devm_` naturally deallocates in reverse
allocation order). This means that during removal, there is a race
condition where an interrupt can fire just _after_ the `power_supply`
handle has been freed, *but* just _before_ the corresponding
unregistration of the IRQ handler has run.
This will lead to the IRQ handler calling `power_supply_changed()` with
a freed `power_supply` handle. Which usually crashes the system or
otherwise silently corrupts the memory...
Note that there is a similar situation which can also happen during
`probe()`; the possibility of an interrupt firing _before_ registering
the `power_supply` handle. This would then lead to the nasty situation
of using the `power_supply` handle *uninitialized* in
`power_supply_changed()`.
Fix this racy use-after-free by making sure the IRQ is requested _after_
the registration of the `power_supply` handle.
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath12k: do WoW offloads only on primary link
In case of multi-link connection, WCN7850 firmware crashes due to WoW
offloads enabled on both primary and secondary links.
Change to do it only on primary link to fix it.
Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00284-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1
In the Linux kernel, the following vulnerability has been resolved:
spi: wpcm-fiu: Fix potential NULL pointer dereference in wpcm_fiu_probe()
platform_get_resource_byname() can return NULL, which would cause a crash
when passed the pointer to resource_size().
Move the fiu->memory_size assignment after the error check for
devm_ioremap_resource() to prevent the potential NULL pointer dereference.
In the Linux kernel, the following vulnerability has been resolved:
ASoC: fsl_xcvr: Revert fix missing lock in fsl_xcvr_mode_put()
This reverts commit f51424872760 ("ASoC: fsl_xcvr: fix missing lock in fsl_xcvr_mode_put()").
The original patch attempted to acquire the card->controls_rwsem lock in
fsl_xcvr_mode_put(). However, this function is called from the upper ALSA
core function snd_ctl_elem_write(), which already holds the write lock on
controls_rwsem for the whole put operation. So there is no need to simply
hold the lock for fsl_xcvr_activate_ctl() again.
Acquiring the read lock while holding the write lock in the same thread
results in a deadlock and a hung task, as reported by Alexander Stein.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix out-of-bounds stream encoder index v3
eng_id can be negative and that stream_enc_regs[]
can be indexed out of bounds.
eng_id is used directly as an index into stream_enc_regs[], which has
only 5 entries. When eng_id is 5 (ENGINE_ID_DIGF) or negative, this can
access memory past the end of the array.
Add a bounds check using ARRAY_SIZE() before using eng_id as an index.
The unsigned cast also rejects negative values.
This avoids out-of-bounds access.
Fixes the below smatch error:
dcn*_resource.c: stream_encoder_create() may index
stream_enc_regs[eng_id] out of bounds (size 5).
drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn351/dcn351_resource.c
1246 static struct stream_encoder *dcn35_stream_encoder_create(
1247 enum engine_id eng_id,
1248 struct dc_context *ctx)
1249 {
...
1255
1256 /* Mapping of VPG, AFMT, DME register blocks to DIO block instance */
1257 if (eng_id <= ENGINE_ID_DIGF) {
ENGINE_ID_DIGF is 5. should <= be <?
Unrelated but, ugh, why is Smatch saying that "eng_id" can be negative?
end_id is type signed long, but there are checks in the caller which prevent it from being negative.
1258 vpg_inst = eng_id;
1259 afmt_inst = eng_id;
1260 } else
1261 return NULL;
1262
...
1281
1282 dcn35_dio_stream_encoder_construct(enc1, ctx, ctx->dc_bios,
1283 eng_id, vpg, afmt,
--> 1284 &stream_enc_regs[eng_id],
^^^^^^^^^^^^^^^^^^^^^^^ This stream_enc_regs[] array has 5 elements so we are one element beyond the end of the array.
...
1287 return &enc1->base;
1288 }
v2: use explicit bounds check as suggested by Roman/Dan; avoid unsigned int cast
v3: The compiler already knows how to compare the two values, so the
cast (int) is not needed. (Roman)
In the Linux kernel, the following vulnerability has been resolved:
drm/xe/pf: Fix sysfs initialization
In case of devm_add_action_or_reset() failure the provided cleanup
action will be run immediately on the not yet initialized kobject.
This may lead to errors like:
[ ] kobject: '(null)' (ff110001393608e0): is not initialized, yet kobject_put() is being called.
[ ] WARNING: lib/kobject.c:734 at kobject_put+0xd9/0x250, CPU#0: kworker/0:0/9
[ ] RIP: 0010:kobject_put+0xdf/0x250
[ ] Call Trace:
[ ] xe_sriov_pf_sysfs_init+0x21/0x100 [xe]
[ ] xe_sriov_pf_init_late+0x87/0x2b0 [xe]
[ ] xe_sriov_init_late+0x5f/0x2c0 [xe]
[ ] xe_device_probe+0x5f2/0xc20 [xe]
[ ] xe_pci_probe+0x396/0x610 [xe]
[ ] local_pci_probe+0x47/0xb0
[ ] refcount_t: underflow; use-after-free.
[ ] WARNING: lib/refcount.c:28 at refcount_warn_saturate+0x68/0xb0, CPU#0: kworker/0:0/9
[ ] RIP: 0010:refcount_warn_saturate+0x68/0xb0
[ ] Call Trace:
[ ] kobject_put+0x174/0x250
[ ] xe_sriov_pf_sysfs_init+0x21/0x100 [xe]
[ ] xe_sriov_pf_init_late+0x87/0x2b0 [xe]
[ ] xe_sriov_init_late+0x5f/0x2c0 [xe]
[ ] xe_device_probe+0x5f2/0xc20 [xe]
[ ] xe_pci_probe+0x396/0x610 [xe]
[ ] local_pci_probe+0x47/0xb0
Fix that by calling kobject_init() and kobject_add() separately
and register cleanup action after the kobject is initialized.
Also make this cleanup registration a part of the create helper to
fix another mistake, as in the loop we were wrongly passing parent
kobject while registering cleanup action, and this resulted in some
undetected leaks.
(cherry picked from commit 98b16727f07e26a5d4de84d88805ce7ffcfdd324)
In the Linux kernel, the following vulnerability has been resolved:
pstore/ram: fix buffer overflow in persistent_ram_save_old()
persistent_ram_save_old() can be called multiple times for the same
persistent_ram_zone (e.g., via ramoops_pstore_read -> ramoops_get_next_prz
for PSTORE_TYPE_DMESG records).
Currently, the function only allocates prz->old_log when it is NULL,
but it unconditionally updates prz->old_log_size to the current buffer
size and then performs memcpy_fromio() using this new size. If the
buffer size has grown since the first allocation (which can happen
across different kernel boot cycles), this leads to:
1. A heap buffer overflow (OOB write) in the memcpy_fromio() calls
2. A subsequent OOB read when ramoops_pstore_read() accesses the buffer
using the incorrect (larger) old_log_size
The KASAN splat would look similar to:
BUG: KASAN: slab-out-of-bounds in ramoops_pstore_read+0x...
Read of size N at addr ... by task ...
The conditions are likely extremely hard to hit:
0. Crash with a ramoops write of less-than-record-max-size bytes.
1. Reboot: ramoops registers, pstore_get_records(0) reads old crash,
allocates old_log with size X
2. Crash handler registered, timer started (if pstore_update_ms >= 0)
3. Oops happens (non-fatal, system continues)
4. pstore_dump() writes oops via ramoops_pstore_write() size Y (>X)
5. pstore_new_entry = 1, pstore_timer_kick() called
6. System continues running (not a panic oops)
7. Timer fires after pstore_update_ms milliseconds
8. pstore_timefunc() → schedule_work() → pstore_dowork() → pstore_get_records(1)
9. ramoops_get_next_prz() → persistent_ram_save_old()
10. buffer_size() returns Y, but old_log is X bytes
11. Y > X: memcpy_fromio() overflows heap
Requirements:
- a prior crash record exists that did not fill the record size
(almost impossible since the crash handler writes as much as it
can possibly fit into the record, capped by max record size and
the kmsg buffer almost always exceeds the max record size)
- pstore_update_ms >= 0 (disabled by default)
- Non-fatal oops (system survives)
Free and reallocate the buffer when the new size differs from the
previously allocated size. This ensures old_log always has sufficient
space for the data being copied.