From: Harin Lee <me@harin.net> mainline inclusion from mainline-v7.0-rc4 commit e9418da50d9e5c496c22fe392e4ad74c038a94eb category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/14346 CVE: CVE-2026-31602 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Commit 391e69143d0a increased CT_PTP_NUM from 1 to 4 to support 256 playback streams, but the additional pages are not used by the card correctly. The CT20K2 hardware already has multiple VMEM_PTPAL registers, but using them separately would require refactoring the entire virtual memory allocation logic. ct_vm_map() always uses PTEs in vm->ptp[0].area regardless of CT_PTP_NUM. On AMD64 systems, a single PTP covers 512 PTEs (2M). When aggregate memory allocations exceed this limit, ct_vm_map() tries to access beyond the allocated space and causes a page fault: BUG: unable to handle page fault for address: ffffd4ae8a10a000 Oops: Oops: 0002 [#1] SMP PTI RIP: 0010:ct_vm_map+0x17c/0x280 [snd_ctxfi] Call Trace: atc_pcm_playback_prepare+0x225/0x3b0 ct_pcm_playback_prepare+0x38/0x60 snd_pcm_do_prepare+0x2f/0x50 snd_pcm_action_single+0x36/0x90 snd_pcm_action_nonatomic+0xbf/0xd0 snd_pcm_ioctl+0x28/0x40 __x64_sys_ioctl+0x97/0xe0 do_syscall_64+0x81/0x610 entry_SYSCALL_64_after_hwframe+0x76/0x7e Revert CT_PTP_NUM to 1. The 256 SRC_RESOURCE_NUM and playback_count remain unchanged. Fixes: 391e69143d0a ("ALSA: ctxfi: Bump playback substreams to 256") Cc: stable@vger.kernel.org Signed-off-by: Harin Lee <me@harin.net> Link: https://patch.msgid.link/20260406074857.216034-1-me@harin.net Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Zhang Yuwei <zhangyuwei20@huawei.com> --- sound/pci/ctxfi/ctvmem.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sound/pci/ctxfi/ctvmem.h b/sound/pci/ctxfi/ctvmem.h index da54cbcdb0be..43a0065b40c3 100644 --- a/sound/pci/ctxfi/ctvmem.h +++ b/sound/pci/ctxfi/ctvmem.h @@ -15,7 +15,7 @@ #ifndef CTVMEM_H #define CTVMEM_H -#define CT_PTP_NUM 4 /* num of device page table pages */ +#define CT_PTP_NUM 1 /* num of device page table pages */ #include <linux/mutex.h> #include <linux/list.h> -- 2.22.0