================================================================== 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 ffff888046dd8408 by task syz.2.5135/21726 CPU: 1 UID: 0 PID: 21726 Comm: syz.2.5135 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: 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+0x2cf/0x390 drivers/gpu/drm/drm_ioctl.c:797 drm_ioctl+0x67f/0xb10 drivers/gpu/drm/drm_ioctl.c:894 __do_compat_sys_ioctl fs/ioctl.c:695 [inline] __se_compat_sys_ioctl fs/ioctl.c:638 [inline] __ia32_compat_sys_ioctl+0x543/0x840 fs/ioctl.c:638 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf709d539 Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f546c55c EFLAGS: 00000206 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00000000c00c642e RDX: 0000000080000300 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 21726: 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+0x5cd/0x910 mm/slub.c:7081 kvmalloc_array_node_noprof include/linux/slab.h:1122 [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+0x2cf/0x390 drivers/gpu/drm/drm_ioctl.c:797 drm_ioctl+0x67f/0xb10 drivers/gpu/drm/drm_ioctl.c:894 __do_compat_sys_ioctl fs/ioctl.c:695 [inline] __se_compat_sys_ioctl fs/ioctl.c:638 [inline] __ia32_compat_sys_ioctl+0x543/0x840 fs/ioctl.c:638 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff888046dd8000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 0 bytes to the right of allocated 1032-byte region [ffff888046dd8000, ffff888046dd8408) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x46dd8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813ffa7000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813ffa7000 dead000000000100 dead000000000122 head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea00011b7601 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 15262, tgid 15250 (syz.2.2985), ts 871304625761, free_ts 870117159572 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+0x2365/0x2440 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3039 [inline] allocate_slab+0x96/0x3a0 mm/slub.c:3212 new_slab mm/slub.c:3266 [inline] ___slab_alloc+0xe94/0x18a0 mm/slub.c:4636 __slab_alloc+0x65/0x100 mm/slub.c:4755 __slab_alloc_node mm/slub.c:4831 [inline] slab_alloc_node mm/slub.c:5253 [inline] __do_kmalloc_node mm/slub.c:5626 [inline] __kmalloc_node_track_caller_noprof+0x5c7/0x800 mm/slub.c:5736 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:601 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1383 [inline] sctp_packet_pack net/sctp/output.c:472 [inline] sctp_packet_transmit+0xf4c/0x2bb0 net/sctp/output.c:621 sctp_outq_flush_transports net/sctp/outqueue.c:1173 [inline] sctp_outq_flush+0xecb/0x3140 net/sctp/outqueue.c:1221 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:-1 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1204 [inline] sctp_do_sm+0x5332/0x5a20 net/sctp/sm_sideeffect.c:1175 sctp_assoc_bh_rcv+0x3f2/0x630 net/sctp/associola.c:1034 sctp_backlog_rcv+0x167/0x3f0 net/sctp/input.c:331 sk_backlog_rcv include/net/sock.h:1158 [inline] __release_sock+0x297/0x3a0 net/core/sock.c:3180 page last free pid 9806 tgid 9806 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:2906 discard_slab mm/slub.c:3310 [inline] __put_partials+0x146/0x170 mm/slub.c:3857 put_cpu_partial+0x1f2/0x2e0 mm/slub.c:3932 __slab_free+0x2b9/0x390 mm/slub.c:5906 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4955 [inline] slab_alloc_node mm/slub.c:5265 [inline] __kmalloc_cache_noprof+0x36f/0x6f0 mm/slub.c:5743 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] nsim_fib4_rt_create drivers/net/netdevsim/fib.c:280 [inline] nsim_fib4_rt_insert drivers/net/netdevsim/fib.c:426 [inline] nsim_fib4_event drivers/net/netdevsim/fib.c:464 [inline] nsim_fib_event+0x4dc/0x8a30 drivers/net/netdevsim/fib.c:884 nsim_fib_event_work+0x249/0x3b0 drivers/net/netdevsim/fib.c:1493 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888046dd8300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888046dd8380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888046dd8400: 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888046dd8480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888046dd8500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 4: 10 07 adc %al,(%rdi) 6: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi a: 10 08 adc %cl,(%rax) c: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 20: 00 51 52 add %dl,0x52(%rcx) 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 ret 2e: 90 nop 2f: 90 nop 30: 90 nop 31: 90 nop 32: 90 nop 33: 90 nop 34: 90 nop 35: 90 nop 36: 90 nop 37: 90 nop 38: 90 nop 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop