CVE-2024-26947

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/[email protected]/