Bugzilla – Bug 1223662
VUL-0: CVE-2024-26947: kernel: ARM: 9359/1: flush: check if the folio is reserved for no-mapping addresses
Last modified: 2024-05-30 13:23:54 UTC
In the Linux kernel, the following vulnerability has been resolved: ARM: 9359/1: flush: check if the folio is reserved for no-mapping addresses Since commit a4d5613c4dc6 ("arm: extend pfn_valid to take into account freed memory map alignment") changes the semantics of pfn_valid() to check presence of the memory map for a PFN. A valid page for an address which is reserved but not mapped by the kernel[1], the system crashed during some uio test with the following memory layout: node 0: [mem 0x00000000c0a00000-0x00000000cc8fffff] node 0: [mem 0x00000000d0000000-0x00000000da1fffff] the uio layout is?0xc0900000, 0x100000 the crash backtrace like: Unable to handle kernel paging request at virtual address bff00000 [...] CPU: 1 PID: 465 Comm: startapp.bin Tainted: G O 5.10.0 #1 Hardware name: Generic DT based system PC is at b15_flush_kern_dcache_area+0x24/0x3c LR is at __sync_icache_dcache+0x6c/0x98 [...] (b15_flush_kern_dcache_area) from (__sync_icache_dcache+0x6c/0x98) (__sync_icache_dcache) from (set_pte_at+0x28/0x54) (set_pte_at) from (remap_pfn_range+0x1a0/0x274) (remap_pfn_range) from (uio_mmap+0x184/0x1b8 [uio]) (uio_mmap [uio]) from (__mmap_region+0x264/0x5f4) (__mmap_region) from (__do_mmap_mm+0x3ec/0x440) (__do_mmap_mm) from (do_mmap+0x50/0x58) (do_mmap) from (vm_mmap_pgoff+0xfc/0x188) (vm_mmap_pgoff) from (ksys_mmap_pgoff+0xac/0xc4) (ksys_mmap_pgoff) from (ret_fast_syscall+0x0/0x5c) Code: e0801001 e2423001 e1c00003 f57ff04f (ee070f3e) ---[ end trace 09cf0734c3805d52 ]--- Kernel panic - not syncing: Fatal exception So check if PG_reserved was set to solve this issue. [1]: https://lore.kernel.org/lkml/Zbtdue57RO0QScJM@linux.ibm.com/ References: http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-26947 https://www.cve.org/CVERecord?id=CVE-2024-26947 https://git.kernel.org/stable/c/0c027c2bad7f5111c51a358b5d392e1a695dabff https://git.kernel.org/stable/c/0c66c6f4e21cb22220cbd8821c5c73fc157d20dc https://git.kernel.org/stable/c/9f7ddc222cae8254e93d5c169a8ae11a49d912a7 https://git.kernel.org/stable/c/fb3a122a978626b33de3367ee1762da934c0f512 https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2024/CVE-2024-26947.mbox https://bugzilla.redhat.com/show_bug.cgi?id=2278167
balcklisted both, as not applicable due to missing folio support in our kernels.