================================================================== BUG: KASAN: slab-use-after-free in __ptep_get arch/arm64/include/asm/pgtable.h:315 [inline] BUG: KASAN: slab-use-after-free in __clear_young_dirty_ptes arch/arm64/include/asm/pgtable.h:1309 [inline] BUG: KASAN: slab-use-after-free in contpte_clear_young_dirty_ptes+0x104/0x214 arch/arm64/mm/contpte.c:389 Read of size 8 at addr ffff00000f1c1000 by task syz-executor.1/3921 CPU: 1 PID: 3921 Comm: syz-executor.1 Tainted: G W 6.10.0-rc1-syzkaller-00027-g4a4be1ad3a6e #0 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x9c/0x11c arch/arm64/kernel/stacktrace.c:317 show_stack+0x18/0x24 arch/arm64/kernel/stacktrace.c:324 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xa4/0xf4 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0xf4/0x5a4 mm/kasan/report.c:488 kasan_report+0xc8/0x108 mm/kasan/report.c:601 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381 __ptep_get arch/arm64/include/asm/pgtable.h:315 [inline] __clear_young_dirty_ptes arch/arm64/include/asm/pgtable.h:1309 [inline] contpte_clear_young_dirty_ptes+0x104/0x214 arch/arm64/mm/contpte.c:389 clear_young_dirty_ptes arch/arm64/include/asm/pgtable.h:1715 [inline] madvise_free_pte_range+0xce8/0x10e0 mm/madvise.c:767 walk_pmd_range mm/pagewalk.c:143 [inline] walk_pud_range mm/pagewalk.c:221 [inline] walk_p4d_range mm/pagewalk.c:256 [inline] walk_pgd_range+0x8e8/0x14a4 mm/pagewalk.c:293 __walk_page_range+0x420/0x5e4 mm/pagewalk.c:395 walk_page_range+0x370/0x6f8 mm/pagewalk.c:521 madvise_free_single_vma+0x300/0x5a8 mm/madvise.c:815 madvise_dontneed_free mm/madvise.c:929 [inline] madvise_vma_behavior+0x30c/0x1028 mm/madvise.c:1046 madvise_walk_vmas+0x114/0x210 mm/madvise.c:1268 do_madvise+0x20c/0x6c4 mm/madvise.c:1464 __do_sys_madvise mm/madvise.c:1481 [inline] __se_sys_madvise mm/madvise.c:1479 [inline] __arm64_sys_madvise+0x88/0xdc mm/madvise.c:1479 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline] invoke_syscall+0x6c/0x25c arch/arm64/kernel/syscall.c:48 el0_svc_common.constprop.0+0xac/0x230 arch/arm64/kernel/syscall.c:133 do_el0_svc+0x40/0x58 arch/arm64/kernel/syscall.c:152 el0_svc+0x50/0x180 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x100/0x12c arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 Allocated by task 3349: kasan_save_stack+0x3c/0x64 mm/kasan/common.c:47 kasan_save_track+0x20/0x3c mm/kasan/common.c:68 kasan_save_alloc_info+0x40/0x54 mm/kasan/generic.c:565 unpoison_slab_object mm/kasan/common.c:312 [inline] __kasan_slab_alloc+0x8c/0x90 mm/kasan/common.c:338 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3940 [inline] slab_alloc_node mm/slub.c:4000 [inline] kmem_cache_alloc_node_noprof+0x148/0x308 mm/slub.c:4043 __alloc_skb+0x208/0x2f0 net/core/skbuff.c:656 alloc_skb include/linux/skbuff.h:1308 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x1ec/0xa40 drivers/net/netdevsim/dev.c:850 process_one_work+0x7bc/0x18a0 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x764/0xc24 kernel/workqueue.c:3393 kthread+0x27c/0x300 kernel/kthread.c:389 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 Freed by task 3349: kasan_save_stack+0x3c/0x64 mm/kasan/common.c:47 kasan_save_track+0x20/0x3c mm/kasan/common.c:68 kasan_save_free_info+0x4c/0x74 mm/kasan/generic.c:579 poison_slab_object+0x114/0x15c mm/kasan/common.c:240 __kasan_slab_free+0x1c/0x44 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2195 [inline] slab_free mm/slub.c:4436 [inline] kmem_cache_free+0x124/0x46c mm/slub.c:4511 kfree_skbmem+0x118/0x1b0 net/core/skbuff.c:1131 __kfree_skb net/core/skbuff.c:1188 [inline] consume_skb net/core/skbuff.c:1409 [inline] consume_skb+0xb4/0x14c net/core/skbuff.c:1403 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x6a0/0xa40 drivers/net/netdevsim/dev.c:850 process_one_work+0x7bc/0x18a0 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x764/0xc24 kernel/workqueue.c:3393 kthread+0x27c/0x300 kernel/kthread.c:389 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 The buggy address belongs to the object at ffff00000f1c1000 which belongs to the cache skbuff_head_cache of size 232 The buggy address is located 0 bytes inside of freed 232-byte region [ffff00000f1c1000, ffff00000f1c10e8) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff00000f1c1140 pfn:0x4f1c1 anon flags: 0x1ffc00000000000(node=0|zone=0|lastcpupid=0x7ff) page_type: 0xffffefff(slab) raw: 01ffc00000000000 ffff00000a995780 0000000000000000 dead000000000001 raw: ffff00000f1c1140 00000000000c0003 00000001ffffefff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff00000f1c0f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff00000f1c0f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff00000f1c1000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff00000f1c1080: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff00000f1c1100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ==================================================================