CVE-2024-53105

In the Linux kernel, the following vulnerability has been resolved:

mm: pagealloc: move mlocked flag clearance into freepages_prepare()

Syzbot reported a bad page state problem caused by a page being freed using freepage() still having a mlocked flag at freepages_prepare() stage:

BUG: Bad page state in process syz.5.504 pfn:61f45 page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x61f45 flags: 0xfff00000080204(referenced|workingset|mlocked|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000080204 0000000000000000 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: PAGEFLAGSCHECKATFREE flag(s) set pageowner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfpmask 0x400dc0(GFPKERNELACCOUNT|_GFPZERO), pid 8443, tgid 8442 (syz.5.504), ts 201884660643, freets 201499827394 setpageowner include/linux/pageowner.h:32 [inline] postallochook+0x1f3/0x230 mm/pagealloc.c:1537 prepnewpage mm/pagealloc.c:1545 [inline] getpagefromfreelist+0x303f/0x3190 mm/pagealloc.c:3457 _allocpagesnoprof+0x292/0x710 mm/pagealloc.c:4733 allocpagesmpolnoprof+0x3e8/0x680 mm/mempolicy.c:2265 kvmcoalescedmmioinit+0x1f/0xf0 virt/kvm/coalescedmmio.c:99 kvmcreatevm virt/kvm/kvmmain.c:1235 [inline] kvmdevioctlcreatevm virt/kvm/kvmmain.c:5488 [inline] kvmdevioctl+0x12dc/0x2240 virt/kvm/kvmmain.c:5530 _docompatsysioctl fs/ioctl.c:1007 [inline] _secompatsysioctl+0x510/0xc90 fs/ioctl.c:950 dosyscall32irqson arch/x86/entry/common.c:165 [inline] _dofastsyscall32+0xb4/0x110 arch/x86/entry/common.c:386 dofastsyscall32+0x34/0x80 arch/x86/entry/common.c:411 entrySYSENTERcompatafterhwframe+0x84/0x8e page last free pid 8399 tgid 8399 stack trace: resetpageowner include/linux/pageowner.h:25 [inline] freepagesprepare mm/pagealloc.c:1108 [inline] freeunreffolios+0xf12/0x18d0 mm/pagealloc.c:2686 foliosputrefs+0x76c/0x860 mm/swap.c:1007 freepagesandswapcache+0x5c8/0x690 mm/swapstate.c:335 _tlbbatchfreeencodedpages mm/mmugather.c:136 [inline] tlbbatchpagesflush mm/mmugather.c:149 [inline] tlbflushmmufree mm/mmugather.c:366 [inline] tlbflushmmu+0x3a3/0x680 mm/mmugather.c:373 tlbfinishmmu+0xd4/0x200 mm/mmugather.c:465 exitmmap+0x496/0xc40 mm/mmap.c:1926 _mmput+0x115/0x390 kernel/fork.c:1348 exitmm+0x220/0x310 kernel/exit.c:571 doexit+0x9b2/0x28e0 kernel/exit.c:926 dogroupexit+0x207/0x2c0 kernel/exit.c:1088 _dosysexitgroup kernel/exit.c:1099 [inline] _sesysexitgroup kernel/exit.c:1097 [inline] _x64sysexitgroup+0x3f/0x40 kernel/exit.c:1097 x64syscall+0x2634/0x2640 arch/x86/include/generated/asm/syscalls64.h:232 dosyscallx64 arch/x86/entry/common.c:52 [inline] dosyscall64+0xf3/0x230 arch/x86/entry/common.c:83 entrySYSCALL64afterhwframe+0x77/0x7f Modules linked in: CPU: 0 UID: 0 PID: 8442 Comm: syz.5.504 Not tainted 6.12.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: <TASK> _dumpstack lib/dumpstack.c:94 [inline] dumpstacklvl+0x241/0x360 lib/dumpstack.c:120 badpage+0x176/0x1d0 mm/pagealloc.c:501 freepageisbad mm/pagealloc.c:918 [inline] freepagesprepare mm/pagealloc.c:1100 [inline] freeunrefpage+0xed0/0xf20 mm/pagealloc.c:2638 kvmdestroyvm virt/kvm/kvmmain.c:1327 [inline] kvmputkvm+0xc75/0x1350 virt/kvm/kvmmain.c:1386 kvmvcpurelease+0x54/0x60 virt/kvm/kvmmain.c:4143 _fput+0x23f/0x880 fs/filetable.c:431 taskworkrun+0x24f/0x310 kernel/taskwork.c:239 exittaskwork include/linux/taskwork.h:43 [inline] doexit+0xa2f/0x28e0 kernel/exit.c:939 dogroupexit+0x207/0x2c0 kernel/exit.c:1088 _dosysexitgroup kernel/exit.c:1099 [in ---truncated---