cbcvebase.
CVE-2023-53326
published 2025-09-16

CVE-2023-53326: In the Linux kernel, the following vulnerability has been resolved: powerpc: Don't try to copy PPR for task with NULL pt_regs powerpc sets up PF_KTHREAD and…

PriorityP420medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.14%
3.4th percentile
In the Linux kernel, the following vulnerability has been resolved: powerpc: Don't try to copy PPR for task with NULL pt_regs powerpc sets up PF_KTHREAD and PF_IO_WORKER with a NULL pt_regs, which from my (arguably very short) checking is not commonly done for other archs. This is fine, except when PF_IO_WORKER's have been created and the task does something that causes a coredump to be generated. Then we get this crash: Kernel attempted to read user page (160) - exploit attempt? (uid: 1000) BUG: Kernel NULL pointer dereference on read at 0x00000160 Faulting instruction address: 0xc0000000000c3a60 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=32 NUMA pSeries Modules linked in: bochs drm_vram_helper drm_kms_helper xts binfmt_misc ecb ctr syscopyarea sysfillrect cbc sysimgblt drm_ttm_helper aes_generic ttm sg libaes evdev joydev virtio_balloon vmx_crypto gf128mul drm dm_mod fuse loop configfs drm_panel_orientation_quirks ip_tables x_tables autofs4 hid_generic usbhid hid xhci_pci xhci_hcd usbcore usb_common sd_mod CPU: 1 PID: 1982 Comm: ppc-crash Not tainted 6.3.0-rc2+ #88 Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries NIP: c0000000000c3a60 LR: c000000000039944 CTR: c0000000000398e0 REGS: c0000000041833b0 TRAP: 0300 Not tainted (6.3.0-rc2+) MSR: 800000000280b033 CR: 88082828 XER: 200400f8 ... NIP memcpy_power7+0x200/0x7d0 LR ppr_get+0x64/0xb0 Call Trace: ppr_get+0x40/0xb0 (unreliable) __regset_get+0x180/0x1f0 regset_get_alloc+0x64/0x90 elf_core_dump+0xb98/0x1b60 do_coredump+0x1c34/0x24a0 get_signal+0x71c/0x1410 do_notify_resume+0x140/0x6f0 interrupt_exit_user_prepare_main+0x29c/0x320 interrupt_exit_user_prepare+0x6c/0xa0 interrupt_return_srr_user+0x8/0x138 Because ppr_get() is trying to copy from a PF_IO_WORKER with a NULL pt_regs. Check for a valid pt_regs in both ppc_get/ppr_set, and return an error if not set. The actual error value doesn't seem to be importa

Affected

16 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.25-1 (bookworm)linux 6.1.25-1 (bookworm)
linuxlinux
linuxlinux>= fa439810cc1b3c927ec24ede17d02467e1b143a1 < 80a4200d51e5a7e046f4a90f5faa5bafd5a60c5880a4200d51e5a7e046f4a90f5faa5bafd5a60c58
linuxlinux>= fa439810cc1b3c927ec24ede17d02467e1b143a1 < 7624973bc15b76d000e8e6f9b8080fcb76d365957624973bc15b76d000e8e6f9b8080fcb76d36595
linuxlinux>= fa439810cc1b3c927ec24ede17d02467e1b143a1 < 064a1c7b0f8403260d77627e62424a72ca26cee2064a1c7b0f8403260d77627e62424a72ca26cee2
linuxlinux>= fa439810cc1b3c927ec24ede17d02467e1b143a1 < 01849382373b867ddcbe7536b9dfa89f3bcea60e01849382373b867ddcbe7536b9dfa89f3bcea60e
linuxlinux>= fa439810cc1b3c927ec24ede17d02467e1b143a1 < fd7276189450110ed835eb0a334e62d2f1c4e3befd7276189450110ed835eb0a334e62d2f1c4e3be
linuxlinux_kernel
linuxlinux_kernel>= 0 < 5.10.178-15.10.178-1
linuxlinux_kernel>= 0 < 6.1.25-16.1.25-1
linuxlinux_kernel>= 0 < 6.1.25-16.1.25-1
linuxlinux_kernel>= 0 < 6.1.25-16.1.25-1
linuxlinux_kernel>= 4.8 < 5.10.1775.10.177
linuxlinux_kernel>= 5.11 < 5.15.1065.15.106
linuxlinux_kernel>= 5.16 < 6.1.236.1.23
linuxlinux_kernel>= 6.2 < 6.2.106.2.10

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
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