High · published December 8, 2025
In the Linux kernel, the following vulnerability has been resolved:
regmap: slimbus: fix bus_context pointer in regmap init calls
Commit 4e65bda8273c ("ASoC: wcd934x: fix error handling in
wcd934x_codec_parse_data()") revealed the problem in the slimbus regmap.
That commit breaks audio playback, for instance, on sdm845 Thundercomm
Dragonboard 845c board:
Unable to handle kernel paging request at virtual address ffff8000847cbad4
...
CPU: 5 UID: 0 PID: 776 Comm: aplay Not tainted 6.18.0-rc1-00028-g7ea30958b305 #11 PREEMPT
Hardware name: Thundercomm Dragonboard 845c (DT)
...
Call trace:
slim_xfer_msg+0x24/0x1ac [slimbus] (P)
slim_read+0x48/0x74 [slimbus]
regmap_slimbus_read+0x18/0x24 [regmap_slimbus]
_regmap_raw_read+0xe8/0x174
_regmap_bus_read+0x44/0x80
_regmap_read+0x60/0xd8
_regmap_update_bits+0xf4/0x140
_regmap_select_page+0xa8/0x124
_regmap_raw_write_impl+0x3b8/0x65c
_regmap_bus_raw_write+0x60/0x80
_regmap_write+0x58/0xc0
regmap_write+0x4c/0x80
wcd934x_hw_params+0x494/0x8b8 [snd_soc_wcd934x]
snd_soc_dai_hw_params+0x3c/0x7c [snd_soc_core]
__soc_pcm_hw_params+0x22c/0x634 [snd_soc_core]
dpcm_be_dai_hw_params+0x1d4/0x38c [snd_soc_core]
dpcm_fe_dai_hw_params+0x9c/0x17c [snd_soc_core]
snd_pcm_hw_params+0x124/0x464 [snd_pcm]
snd_pcm_common_ioctl+0x110c/0x1820 [snd_pcm]
snd_pcm_ioctl+0x34/0x4c [snd_pcm]
__arm64_sys_ioctl+0xac/0x104
invoke_syscall+0x48/0x104
el0_svc_common.constprop.0+0x40/0xe0
do_el0_svc+0x1c/0x28
el0_svc+0x34/0xec
el0t_64_sync_handler+0xa0/0xf0
el0t_64_sync+0x198/0x19c
The __devm_regmap_init_slimbus() started to be used instead of
__regmap_init_slimbus() after the commit mentioned above and turns out
the incorrect bus_context pointer (3rd argument) was used in
__devm_regmap_init_slimbus(). It should be just "slimbus" (which is equal
to &slimbus->dev). Correct it. The wcd934x codec seems to be the only or
the first user of devm_regmap_init_slimbus() but we should fix it till
the point where __devm_regmap_init_slimbus() was introduced therefore
two "Fixes" tags.
While at this, also correct the same argument in __regmap_init_slimbus().