CVE - CVE-2023-52499

CVE-ID
CVE-2023-52499	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
Description
In the Linux kernel, the following vulnerability has been resolved: powerpc/47x: Fix 47x syscall return crash Eddie reported that newer kernels were crashing during boot on his 476 FSP2 system: kernel tried to execute user page (b7ee2000) - exploit attempt? (uid: 0) BUG: Unable to handle kernel instruction fetch Faulting instruction address: 0xb7ee2000 Oops: Kernel access of bad area, sig: 11 [#1] BE PAGE_SIZE=4K FSP-2 Modules linked in: CPU: 0 PID: 61 Comm: mount Not tainted 6.1.55-d23900f.ppcnf-fsp2 #1 Hardware name: ibm,fsp2 476fpe 0x7ff520c0 FSP-2 NIP: b7ee2000 LR: 8c008000 CTR: 00000000 REGS: bffebd83 TRAP: 0400 Not tainted (6.1.55-d23900f.ppcnf-fs p2) MSR: 00000030 <IR,DR> CR: 00001000 XER: 20000000 GPR00: c00110ac bffebe63 bffebe7e bffebe88 8c008000 00001000 00000d12 b7ee2000 GPR08: 00000033 00000000 00000000 c139df10 48224824 1016c314 10160000 00000000 GPR16: 10160000 10160000 00000008 00000000 10160000 00000000 10160000 1017f5b0 GPR24: 1017fa50 1017f4f0 1017fa50 1017f740 1017f630 00000000 00000000 1017f4f0 NIP [b7ee2000] 0xb7ee2000 LR [8c008000] 0x8c008000 Call Trace: Instruction dump: XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX ---[ end trace 0000000000000000 ]--- The problem is in ret_from_syscall where the check for icache_44x_need_flush is done. When the flush is needed the code jumps out-of-line to do the flush, and then intends to jump back to continue the syscall return. However the branch back to label 1b doesn't return to the correct location, instead branching back just prior to the return to userspace, causing bogus register values to be used by the rfi. The breakage was introduced by commit 6f76a01173cc ("powerpc/syscall: implement system call entry/exit logic in C for PPC32") which inadvertently removed the "1" label and reused it elsewhere. Fix it by adding named local labels in the correct locations. Note that the return label needs to be outside the ifdef so that CONFIG_PPC_47x=n compiles.
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
MISC:https://git.kernel.org/stable/c/29017ab1a539101d9c7bec63cc13a019f97b2820 URL:https://git.kernel.org/stable/c/29017ab1a539101d9c7bec63cc13a019f97b2820 MISC:https://git.kernel.org/stable/c/70f6756ad96dd70177dddcfac2fe4bd4bb320746 URL:https://git.kernel.org/stable/c/70f6756ad96dd70177dddcfac2fe4bd4bb320746 MISC:https://git.kernel.org/stable/c/8ac2689502f986a46f4221e239d4ff2897f1ccb3 URL:https://git.kernel.org/stable/c/8ac2689502f986a46f4221e239d4ff2897f1ccb3 MISC:https://git.kernel.org/stable/c/f0eee815babed70a749d2496a7678be5b45b4c14 URL:https://git.kernel.org/stable/c/f0eee815babed70a749d2496a7678be5b45b4c14
Assigning CNA
kernel.org
Date Record Created
20240220	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20240220)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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