CVE-2025-40317: 
Linux Debian vulnerability analysis and mitigation

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().