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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 ffff8880754c3c60 by task syz.9.1136/10857

CPU: 0 UID: 0 PID: 10857 Comm: syz.9.1136 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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_pin_locked+0x22c/0x460 drivers/gpu/drm/drm_gem_shmem_helper.c:261
 drm_gem_map_attach+0x19c/0x1f0 drivers/gpu/drm/drm_prime.c:620
 dma_buf_dynamic_attach+0x1ea/0x3d0 drivers/dma-buf/dma-buf.c:974
 drm_gem_shmem_prime_import_no_map+0xc1/0x2f0 drivers/gpu/drm/drm_gem_shmem_helper.c:835
 drm_gem_prime_fd_to_handle+0x196/0x4d0 drivers/gpu/drm/drm_prime.c:313
 drm_ioctl_kernel+0x2cc/0x390 drivers/gpu/drm/drm_ioctl.c:797
 drm_ioctl+0x67f/0xb10 drivers/gpu/drm/drm_ioctl.c:894
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:598 [inline]
 __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:584
 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: 0033:0x7fcb2fd8ebe9
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:00007fcb30bd7038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fcb2ffc5fa0 RCX: 00007fcb2fd8ebe9
RDX: 0000200000000300 RSI: 00000000c00c642e RDI: 0000000000000004
RBP: 00007fcb2fe11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcb2ffc6038 R14: 00007fcb2ffc5fa0 R15: 00007ffe3bff5d28
 </TASK>

Allocated by task 10857:
 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:397 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:5366 [inline]
 __kvmalloc_node_noprof+0x5cd/0x910 mm/slub.c:6527
 kvmalloc_array_node_noprof include/linux/slab.h:1118 [inline]
 drm_gem_get_pages+0x166/0xa20 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_pin_locked+0x22c/0x460 drivers/gpu/drm/drm_gem_shmem_helper.c:261
 drm_gem_map_attach+0x19c/0x1f0 drivers/gpu/drm/drm_prime.c:620
 dma_buf_dynamic_attach+0x1ea/0x3d0 drivers/dma-buf/dma-buf.c:974
 drm_gem_shmem_prime_import_no_map+0xc1/0x2f0 drivers/gpu/drm/drm_gem_shmem_helper.c:835
 drm_gem_prime_fd_to_handle+0x196/0x4d0 drivers/gpu/drm/drm_prime.c:313
 drm_ioctl_kernel+0x2cc/0x390 drivers/gpu/drm/drm_ioctl.c:797
 drm_ioctl+0x67f/0xb10 drivers/gpu/drm/drm_ioctl.c:894
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:598 [inline]
 __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:584
 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 ffff8880754c3c00
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 0 bytes to the right of
 allocated 96-byte region [ffff8880754c3c00, ffff8880754c3c60)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x754c3
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801a841280 ffffea0001658300 dead000000000002
raw: 0000000000000000 0000000000200020 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 36, tgid 36 (kworker/u8:2), ts 97257117074, free_ts 97120874387
 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+0x21e4/0x22c0 mm/page_alloc.c:3863
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5153
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:2996 [inline]
 allocate_slab+0x8a/0x330 mm/slub.c:3164
 new_slab mm/slub.c:3218 [inline]
 ___slab_alloc+0xbd1/0x13f0 mm/slub.c:4420
 __slab_alloc+0x55/0xa0 mm/slub.c:4511
 __slab_alloc_node mm/slub.c:4586 [inline]
 slab_alloc_node mm/slub.c:4996 [inline]
 __kmalloc_cache_noprof+0x411/0x6f0 mm/slub.c:5392
 kmalloc_noprof include/linux/slab.h:956 [inline]
 kzalloc_noprof include/linux/slab.h:1090 [inline]
 nsim_fib_event_schedule_work drivers/net/netdevsim/fib.c:990 [inline]
 nsim_fib_event_nb+0x187/0x1080 drivers/net/netdevsim/fib.c:1043
 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85
 atomic_notifier_call_chain+0xda/0x180 kernel/notifier.c:223
 call_fib_notifiers+0x31/0x60 net/core/fib_notifier.c:35
 call_fib6_entry_notifiers net/ipv6/ip6_fib.c:409 [inline]
 fib6_add_rt2node+0x15fb/0x33a0 net/ipv6/ip6_fib.c:1244
 fib6_add+0x8da/0x18a0 net/ipv6/ip6_fib.c:1528
 __ip6_ins_rt net/ipv6/route.c:1351 [inline]
 ip6_ins_rt+0xc8/0x120 net/ipv6/route.c:1361
 __ipv6_ifa_notify+0x63f/0xac0 net/ipv6/addrconf.c:6283
page last free pid 15 tgid 15 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2900
 rcu_do_batch kernel/rcu/tree.c:2605 [inline]
 rcu_core+0xcab/0x1770 kernel/rcu/tree.c:2861
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:968
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff8880754c3b00: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
 ffff8880754c3b80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
>ffff8880754c3c00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
                                                       ^
 ffff8880754c3c80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
 ffff8880754c3d00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
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