================================================================== BUG: KASAN: slab-out-of-bounds in ext4_ext_binsearch fs/ext4/extents.c:826 [inline] BUG: KASAN: slab-out-of-bounds in ext4_find_extent+0xbeb/0xe20 fs/ext4/extents.c:945 Read of size 4 at addr ffff888110a53c98 by task syz.0.23/414 CPU: 1 PID: 414 Comm: syz.0.23 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0xe2/0x130 mm/kasan/report.c:452 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 ext4_ext_binsearch fs/ext4/extents.c:826 [inline] ext4_find_extent+0xbeb/0xe20 fs/ext4/extents.c:945 ext4_ext_map_blocks+0x20b/0x5dd0 fs/ext4/extents.c:4160 ext4_map_blocks+0x3b1/0x1bd0 fs/ext4/inode.c:601 ext4_mpage_readpages+0xa05/0x2110 fs/ext4/readpage.c:343 ext4_readahead+0xe4/0x110 fs/ext4/inode.c:3352 read_pages+0x17b/0xb60 mm/readahead.c:140 page_cache_ra_unbounded+0x693/0x7e0 mm/readahead.c:248 do_page_cache_ra+0xf2/0x110 mm/readahead.c:277 ondemand_readahead+0x9ca/0xc00 mm/readahead.c:532 page_cache_sync_ra+0x250/0x2a0 mm/readahead.c:587 page_cache_sync_readahead include/linux/pagemap.h:837 [inline] generic_file_buffered_read+0x574/0x2770 mm/filemap.c:2250 generic_file_read_iter+0x11e/0x5c0 mm/filemap.c:2568 ext4_file_read_iter+0x3cc/0x530 fs/ext4/file.c:-1 call_read_iter include/linux/fs.h:2060 [inline] new_sync_read fs/read_write.c:415 [inline] vfs_read+0x62a/0xa60 fs/read_write.c:496 ksys_read+0x149/0x250 fs/read_write.c:634 __do_sys_read fs/read_write.c:644 [inline] __se_sys_read fs/read_write.c:642 [inline] __x64_sys_read+0x7b/0x90 fs/read_write.c:642 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f96d6f77799 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f96d59d2028 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f96d71f0fa0 RCX: 00007f96d6f77799 RDX: 0000000000002020 RSI: 0000200000001e00 RDI: 0000000000000004 RBP: 00007f96d700dbd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f96d71f1038 R14: 00007f96d71f0fa0 R15: 00007fffcf1fcaf8 Allocated by task 364: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:430 [inline] ____kasan_kmalloc mm/kasan/common.c:509 [inline] __kasan_kmalloc+0xda/0x110 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] kmem_cache_alloc_trace+0x181/0x2e0 mm/slub.c:2979 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:667 [inline] ipv6_add_dev+0xd2/0x10a0 net/ipv6/addrconf.c:381 addrconf_notify+0x582/0xe90 net/ipv6/addrconf.c:3571 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0x90/0x100 kernel/notifier.c:410 call_netdevice_notifiers_info net/core/dev.c:2054 [inline] call_netdevice_notifiers_extack net/core/dev.c:2066 [inline] call_netdevice_notifiers+0x119/0x190 net/core/dev.c:2080 register_netdevice+0x1056/0x13e0 net/core/dev.c:10087 ppp_unit_register drivers/net/ppp/ppp_generic.c:1117 [inline] ppp_dev_configure+0x814/0xac0 drivers/net/ppp/ppp_generic.c:1173 ppp_create_interface drivers/net/ppp/ppp_generic.c:3184 [inline] ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:958 [inline] ppp_ioctl+0x6d5/0x15d0 drivers/net/ppp/ppp_generic.c:657 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0x121/0x1a0 fs/ioctl.c:739 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:739 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 12: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4a/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370 kasan_slab_free include/linux/kasan.h:220 [inline] slab_free_hook mm/slub.c:1600 [inline] slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626 slab_free mm/slub.c:3208 [inline] kfree+0xc0/0x270 mm/slub.c:4196 in6_dev_finish_destroy_rcu+0x8c/0xa0 net/ipv6/addrconf_core.c:250 rcu_do_batch+0x4ef/0xab0 kernel/rcu/tree.c:2494 rcu_core+0x577/0xd80 kernel/rcu/tree.c:2735 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2748 __do_softirq+0x255/0x563 kernel/softirq.c:309 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 __call_rcu kernel/rcu/tree.c:2980 [inline] call_rcu+0x11a/0x10b0 kernel/rcu/tree.c:3054 in6_dev_finish_destroy+0x147/0x180 net/ipv6/addrconf_core.c:271 in6_dev_put include/net/addrconf.h:420 [inline] addrconf_ifdown+0x165c/0x1850 net/ipv6/addrconf.c:3943 addrconf_notify+0x3bd/0xe90 net/ipv6/addrconf.c:-1 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0x90/0x100 kernel/notifier.c:410 call_netdevice_notifiers_info net/core/dev.c:2054 [inline] call_netdevice_notifiers_extack net/core/dev.c:2066 [inline] call_netdevice_notifiers net/core/dev.c:2080 [inline] unregister_netdevice_many+0x1074/0x1a80 net/core/dev.c:10767 unregister_netdevice_queue+0x324/0x370 net/core/dev.c:10701 unregister_netdevice include/linux/netdevice.h:2937 [inline] ppp_release+0xef/0x1f0 drivers/net/ppp/ppp_generic.c:417 __fput+0x2fb/0x770 fs/file_table.c:281 ____fput+0x15/0x20 fs/file_table.c:314 task_work_run+0x127/0x190 kernel/task_work.c:189 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:274 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff888110a53800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 152 bytes to the right of 1024-byte region [ffff888110a53800, ffff888110a53c00) The buggy address belongs to the page: page:ffffea0004429400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x110a50 head:ffffea0004429400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 ffffea0004426200 0000000300000003 ffff888100042f00 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 94, ts 3617627153, free_ts 0 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x179/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x223b/0x23d0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x290/0x620 mm/page_alloc.c:5370 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2a6/0x450 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] __kmalloc_track_caller+0x1ec/0x320 mm/slub.c:4541 __kmalloc_reserve net/core/skbuff.c:144 [inline] __alloc_skb+0xdc/0x520 net/core/skbuff.c:212 alloc_skb include/linux/skbuff.h:1126 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1178 [inline] netlink_sendmsg+0x605/0xb50 net/netlink/af_netlink.c:1889 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2376 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2430 __sys_sendmsg net/socket.c:2459 [inline] __do_sys_sendmsg net/socket.c:2468 [inline] __se_sys_sendmsg net/socket.c:2466 [inline] __x64_sys_sendmsg+0x1f9/0x2c0 net/socket.c:2466 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb page_owner free stack trace missing Memory state around the buggy address: ffff888110a53b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888110a53c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888110a53c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888110a53d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888110a53d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================