syzbot

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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_flush arch/x86/mm/pat/set_memory.c:449 [inline]
BUG: KASAN: slab-out-of-bounds in change_page_attr_set_clr+0x625/0xfc0 arch/x86/mm/pat/set_memory.c:2115
Read of size 8 at addr ffff8880278b46f8 by task syz.0.17/6066

CPU: 1 UID: 0 PID: 6066 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 __cpa_addr arch/x86/mm/pat/set_memory.c:309 [inline]
 cpa_flush arch/x86/mm/pat/set_memory.c:449 [inline]
 change_page_attr_set_clr+0x625/0xfc0 arch/x86/mm/pat/set_memory.c:2115
 cpa_set_pages_array arch/x86/mm/pat/set_memory.c:2137 [inline]
 _set_pages_array+0x145/0x270 arch/x86/mm/pat/set_memory.c:2521
 drm_gem_shmem_get_pages_locked+0x2d0/0x440 drivers/gpu/drm/drm_gem_shmem_helper.c:214
 drm_gem_shmem_mmap+0x193/0x450 drivers/gpu/drm/drm_gem_shmem_helper.c:646
 drm_gem_mmap_obj+0x18a/0x4e0 drivers/gpu/drm/drm_gem.c:1167
 drm_gem_mmap+0x38d/0x640 drivers/gpu/drm/drm_gem.c:1245
 vfs_mmap include/linux/fs.h:2405 [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 mm/vma.c:2670 [inline]
 mmap_region+0x18c9/0x20f0 mm/vma.c:2740
 do_mmap+0xc23/0x10c0 mm/mmap.c:558
 vm_mmap_pgoff+0x2a9/0x4d0 mm/util.c:581
 ksys_mmap_pgoff+0x4e9/0x720 mm/mmap.c:604
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f638ff1efc9
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:00007ffdc97f1258 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f6390175fa0 RCX: 00007f638ff1efc9
RDX: 0000000000000004 RSI: 0000000000004000 RDI: 0000200000001000
RBP: 00007f638ffa1f91 R08: 0000000000000003 R09: 0000000100000000
R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6390175fa0 R14: 00007f6390175fa0 R15: 0000000000000006
 </TASK>

Allocated by task 6066:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417
 kasan_kmalloc include/linux/kasan.h:262 [inline]
 __do_kmalloc_node mm/slub.c:5627 [inline]
 __kvmalloc_node_noprof+0x3fd/0x920 mm/slub.c:7081
 kvmalloc_array_node_noprof include/linux/slab.h:1122 [inline]
 drm_gem_get_pages+0x169/0xa30 drivers/gpu/drm/drm_gem.c:647
 drm_gem_shmem_get_pages_locked+0x201/0x440 drivers/gpu/drm/drm_gem_shmem_helper.c:200
 drm_gem_shmem_mmap+0x193/0x450 drivers/gpu/drm/drm_gem_shmem_helper.c:646
 drm_gem_mmap_obj+0x18a/0x4e0 drivers/gpu/drm/drm_gem.c:1167
 drm_gem_mmap+0x38d/0x640 drivers/gpu/drm/drm_gem.c:1245
 vfs_mmap include/linux/fs.h:2405 [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 mm/vma.c:2670 [inline]
 mmap_region+0x18c9/0x20f0 mm/vma.c:2740
 do_mmap+0xc23/0x10c0 mm/mmap.c:558
 vm_mmap_pgoff+0x2a9/0x4d0 mm/util.c:581
 ksys_mmap_pgoff+0x4e9/0x720 mm/mmap.c:604
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880278b4600
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 0 bytes to the right of
 allocated 248-byte region [ffff8880278b4600, ffff8880278b46f8)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x278b4
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x80000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000040 ffff88813ff26b40 ffffea00009f2480 dead000000000004
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 0080000000000040 ffff88813ff26b40 ffffea00009f2480 dead000000000004
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 0080000000000001 ffffea00009e2d01 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 70, tgid 70 (kworker/u8:5), ts 14447348561, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850
 prep_new_page mm/page_alloc.c:1858 [inline]
 get_page_from_freelist+0x28c0/0x2960 mm/page_alloc.c:3884
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183
 alloc_slab_page mm/slub.c:3041 [inline]
 allocate_slab+0x71/0x3a0 mm/slub.c:3212
 new_slab mm/slub.c:3266 [inline]
 ___slab_alloc+0xb12/0x13f0 mm/slub.c:4636
 __slab_alloc+0xc6/0x1f0 mm/slub.c:4755
 __slab_alloc_node mm/slub.c:4831 [inline]
 slab_alloc_node mm/slub.c:5253 [inline]
 __kmalloc_cache_node_noprof+0x1a0/0x700 mm/slub.c:5756
 kmalloc_node_noprof include/linux/slab.h:983 [inline]
 blk_alloc_flush_queue+0x7f/0x240 block/blk-flush.c:483
 blk_mq_init_hctx block/blk-mq.c:3965 [inline]
 blk_mq_alloc_and_init_hctx+0x79e/0xd50 block/blk-mq.c:4507
 __blk_mq_realloc_hw_ctxs+0x169/0x400 block/blk-mq.c:4534
 blk_mq_realloc_hw_ctxs block/blk-mq.c:4561 [inline]
 blk_mq_init_allocated_queue+0x416/0x14e0 block/blk-mq.c:4593
 blk_mq_alloc_queue+0x191/0x280 block/blk-mq.c:4403
 scsi_alloc_sdev+0x785/0xb60 drivers/scsi/scsi_scan.c:339
 scsi_probe_and_add_lun+0x1c5/0x4580 drivers/scsi/scsi_scan.c:1211
 __scsi_scan_target+0x1dd/0xd10 drivers/scsi/scsi_scan.c:1776
 scsi_scan_channel drivers/scsi/scsi_scan.c:1864 [inline]
 scsi_scan_host_selected+0x375/0x690 drivers/scsi/scsi_scan.c:1893
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8880278b4580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880278b4600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880278b4680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc
                                                                ^
 ffff8880278b4700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880278b4780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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