================================================================== 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 ffff88812c3a1e18 by task syz.6.119/1052 CPU: 0 PID: 1052 Comm: syz.6.119 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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_shift_extents+0xc9/0x14a0 fs/ext4/extents.c:5188 ext4_collapse_range fs/ext4/extents.c:5436 [inline] ext4_fallocate+0x109c/0x1a70 fs/ext4/extents.c:4769 vfs_fallocate+0x4b4/0x590 fs/open.c:310 ksys_fallocate fs/open.c:333 [inline] __do_sys_fallocate fs/open.c:341 [inline] __se_sys_fallocate fs/open.c:339 [inline] __x64_sys_fallocate+0xc0/0x110 fs/open.c:339 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fb7894af819 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:00007fb7892f1028 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007fb789729090 RCX: 00007fb7894af819 RDX: 0000000000004000 RSI: 0000000000000008 RDI: 0000000000000007 RBP: 00007fb789545c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000008000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb789729128 R14: 00007fb789729090 R15: 00007fffa02a4578 Allocated by task 95: 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] kobject_uevent_env+0x272/0x700 lib/kobject_uevent.c:539 kobject_synth_uevent+0x57e/0xbb0 lib/kobject_uevent.c:208 uevent_store+0x25/0x60 drivers/base/core.c:2320 dev_attr_store+0x5e/0x80 drivers/base/core.c:2018 sysfs_kf_write+0x129/0x150 fs/sysfs/file.c:139 kernfs_fop_write_iter+0x2c5/0x400 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2066 [inline] new_sync_write fs/read_write.c:518 [inline] vfs_write+0x758/0xdc0 fs/read_write.c:605 ksys_write+0x149/0x250 fs/read_write.c:658 __do_sys_write fs/read_write.c:670 [inline] __se_sys_write fs/read_write.c:667 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:667 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 95: 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 kobject_uevent_env+0x34d/0x700 lib/kobject_uevent.c:641 kobject_synth_uevent+0x57e/0xbb0 lib/kobject_uevent.c:208 uevent_store+0x25/0x60 drivers/base/core.c:2320 dev_attr_store+0x5e/0x80 drivers/base/core.c:2018 sysfs_kf_write+0x129/0x150 fs/sysfs/file.c:139 kernfs_fop_write_iter+0x2c5/0x400 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2066 [inline] new_sync_write fs/read_write.c:518 [inline] vfs_write+0x758/0xdc0 fs/read_write.c:605 ksys_write+0x149/0x250 fs/read_write.c:658 __do_sys_write fs/read_write.c:670 [inline] __se_sys_write fs/read_write.c:667 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:667 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff88812c3a0000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 3608 bytes to the right of 4096-byte region [ffff88812c3a0000, ffff88812c3a1000) The buggy address belongs to the page: page:ffffea0004b0e800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12c3a0 head:ffffea0004b0e800 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100042c00 raw: 0000000000000000 0000000000040004 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 297, ts 23443372575, 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:5384 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 kmemdup+0x26/0x60 mm/util.c:131 __addrconf_sysctl_register+0xb6/0x3e0 net/ipv6/addrconf.c:7046 addrconf_sysctl_register+0x147/0x1a0 net/ipv6/addrconf.c:7111 ipv6_add_dev+0xbaf/0x10a0 net/ipv6/addrconf.c:450 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:10100 __ip_tunnel_create+0x2c7/0x390 net/ipv4/ip_tunnel.c:267 page_owner free stack trace missing Memory state around the buggy address: ffff88812c3a1d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88812c3a1d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88812c3a1e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88812c3a1e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88812c3a1f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================