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BUG: KASAN: slab-out-of-bounds in __cpa_addr arch/x86/mm/pat/set_memory.c:309 [inline]
BUG: KASAN: slab-out-of-bounds in __cpa_addr+0x1d3/0x220 arch/x86/mm/pat/set_memory.c:306
Read of size 8 at addr ffff88801f75e8f8 by task syz.0.17/5978

CPU: 0 UID: 0 PID: 5978 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xcd/0x630 mm/kasan/report.c:482
 kasan_report+0xe0/0x110 mm/kasan/report.c:595
 __cpa_addr arch/x86/mm/pat/set_memory.c:309 [inline]
 __cpa_addr+0x1d3/0x220 arch/x86/mm/pat/set_memory.c:306
 cpa_flush+0x28b/0x8a0 arch/x86/mm/pat/set_memory.c:449
 change_page_attr_set_clr+0x34e/0x4a0 arch/x86/mm/pat/set_memory.c:2115
 cpa_set_pages_array arch/x86/mm/pat/set_memory.c:2137 [inline]
 _set_pages_array+0x1ab/0x2c0 arch/x86/mm/pat/set_memory.c:2521
 drm_gem_shmem_get_pages_locked+0x384/0x490 drivers/gpu/drm/drm_gem_shmem_helper.c:214
 drm_gem_shmem_mmap drivers/gpu/drm/drm_gem_shmem_helper.c:646 [inline]
 drm_gem_shmem_mmap+0xc9/0x550 drivers/gpu/drm/drm_gem_shmem_helper.c:620
 drm_gem_mmap_obj+0x1b5/0x560 drivers/gpu/drm/drm_gem.c:1167
 drm_gem_mmap+0x40b/0x620 drivers/gpu/drm/drm_gem.c:1245
 vfs_mmap include/linux/fs.h:2404 [inline]
 mmap_file mm/internal.h:167 [inline]
 __mmap_new_file_vma mm/vma.c:2413 [inline]
 __mmap_new_vma mm/vma.c:2476 [inline]
 __mmap_region+0x1306/0x27a0 mm/vma.c:2670
 mmap_region+0x1ab/0x3f0 mm/vma.c:2740
 do_mmap+0xa3e/0x1210 mm/mmap.c:558
 vm_mmap_pgoff+0x29e/0x470 mm/util.c:580
 ksys_mmap_pgoff+0x32c/0x5c0 mm/mmap.c:604
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
 __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f825658eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcee652688 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f82567e5fa0 RCX: 00007f825658eec9
RDX: 0000000000000004 RSI: 0000000000004000 RDI: 0000200000001000
RBP: 00007f8256611f91 R08: 0000000000000003 R09: 0000000100000000
R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f82567e5fa0 R14: 00007f82567e5fa0 R15: 0000000000000006
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88801f75fc00 pfn:0x1f75c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f8(unknown)
raw: 00fff00000000040 0000000000000000 dead000000000122 0000000000000000
raw: ffff88801f75fc00 0000000000000000 00000000f8000000 0000000000000000
head: 00fff00000000040 0000000000000000 dead000000000122 0000000000000000
head: ffff88801f75fc00 0000000000000000 00000000f8000000 0000000000000000
head: 00fff00000000002 ffffea00007dd701 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x428c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_COMP), pid 5978, tgid 5978 (syz.0.17), ts 72327313076, free_ts 72326414796
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1850
 prep_new_page mm/page_alloc.c:1858 [inline]
 get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3884
 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5183
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
 ___kmalloc_large_node+0xed/0x160 mm/slub.c:5544
 __kmalloc_large_node_noprof+0x1c/0x70 mm/slub.c:5575
 __do_kmalloc_node mm/slub.c:5591 [inline]
 __kvmalloc_node_noprof.cold+0xf/0x66 mm/slub.c:7036
 kvmalloc_array_node_noprof include/linux/slab.h:1122 [inline]
 drm_gem_get_pages+0x144/0xa10 drivers/gpu/drm/drm_gem.c:647
 drm_gem_shmem_get_pages_locked+0x1e6/0x490 drivers/gpu/drm/drm_gem_shmem_helper.c:200
 drm_gem_shmem_mmap drivers/gpu/drm/drm_gem_shmem_helper.c:646 [inline]
 drm_gem_shmem_mmap+0xc9/0x550 drivers/gpu/drm/drm_gem_shmem_helper.c:620
 drm_gem_mmap_obj+0x1b5/0x560 drivers/gpu/drm/drm_gem.c:1167
 drm_gem_mmap+0x40b/0x620 drivers/gpu/drm/drm_gem.c:1245
 vfs_mmap include/linux/fs.h:2404 [inline]
 mmap_file mm/internal.h:167 [inline]
 __mmap_new_file_vma mm/vma.c:2413 [inline]
 __mmap_new_vma mm/vma.c:2476 [inline]
 __mmap_region+0x1306/0x27a0 mm/vma.c:2670
 mmap_region+0x1ab/0x3f0 mm/vma.c:2740
 do_mmap+0xa3e/0x1210 mm/mmap.c:558
 vm_mmap_pgoff+0x29e/0x470 mm/util.c:580
page last free pid 5978 tgid 5978 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906
 stack_depot_save_flags+0x352/0x9c0 lib/stackdepot.c:727
 kasan_save_stack+0x42/0x60 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:77
 poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417
 kasan_kmalloc include/linux/kasan.h:262 [inline]
 __do_kmalloc_node mm/slub.c:5603 [inline]
 __kmalloc_node_noprof+0x347/0x8a0 mm/slub.c:5609
 kmalloc_array_node_noprof include/linux/slab.h:1075 [inline]
 alloc_slab_obj_exts+0x3a/0xd0 mm/slub.c:2115
 __memcg_slab_post_alloc_hook+0x251/0x940 mm/memcontrol.c:3172
 memcg_slab_post_alloc_hook mm/slub.c:2313 [inline]
 slab_post_alloc_hook mm/slub.c:4957 [inline]
 slab_alloc_node mm/slub.c:5245 [inline]
 kmem_cache_alloc_noprof+0x550/0x6e0 mm/slub.c:5252
 anon_vma_chain_alloc mm/rmap.c:141 [inline]
 anon_vma_clone+0xd8/0x5c0 mm/rmap.c:287
 __split_vma+0x65e/0x1070 mm/vma.c:535
 vms_gather_munmap_vmas+0x1cb/0x1340 mm/vma.c:1359
 __mmap_prepare mm/vma.c:2359 [inline]
 __mmap_region+0x434/0x27a0 mm/vma.c:2652
 mmap_region+0x1ab/0x3f0 mm/vma.c:2740
 do_mmap+0xa3e/0x1210 mm/mmap.c:558
 vm_mmap_pgoff+0x29e/0x470 mm/util.c:580

Memory state around the buggy address:
 ffff88801f75e780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88801f75e800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88801f75e880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fe
                                                                ^
 ffff88801f75e900: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
 ffff88801f75e980: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
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