syzbot ci has tested the following series [v1] bpf: refactor max_depth computation in bpf_get_stack() https://lore.kernel.org/all/20250807175032.7381-1-contact@xxxxxxxxxxxxxx * [PATCH 1/2] bpf: refactor max_depth computation in bpf_get_stack() * [PATCH 2/2] bpf: fix stackmap overflow check in __bpf_get_stackid() and found the following issues: * KASAN: stack-out-of-bounds Write in __bpf_get_stack * PANIC: double fault in its_return_thunk Full report is available here: https://ci.syzbot.org/series/2af1b227-99e3-4e64-ac23-827848a4b8a5 *** KASAN: stack-out-of-bounds Write in __bpf_get_stack tree: bpf-next URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/bpf/bpf-next.git base: f3af62b6cee8af9f07012051874af2d2a451f0e5 arch: amd64 compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 config: https://ci.syzbot.org/builds/5e5c6698-7b84-4bf2-a1ee-1b6223c8d4c3/config C repro: https://ci.syzbot.org/findings/1355d710-d133-43fd-9061-18b2de6844a4/c_repro syz repro: https://ci.syzbot.org/findings/1355d710-d133-43fd-9061-18b2de6844a4/syz_repro netdevsim netdevsim1 netdevsim0: renamed from eth0 netdevsim netdevsim1 netdevsim1: renamed from eth1 ================================================================== BUG: KASAN: stack-out-of-bounds in __bpf_get_stack+0x54a/0xa70 kernel/bpf/stackmap.c:501 Write of size 208 at addr ffffc90003655ee8 by task syz-executor/5952 CPU: 1 UID: 0 PID: 5952 Comm: syz-executor Not tainted 6.16.0-syzkaller-11113-gf3af62b6cee8-dirty #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 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 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:189 __asan_memcpy+0x40/0x70 mm/kasan/shadow.c:106 __bpf_get_stack+0x54a/0xa70 kernel/bpf/stackmap.c:501 ____bpf_get_stack kernel/bpf/stackmap.c:525 [inline] bpf_get_stack+0x33/0x50 kernel/bpf/stackmap.c:522 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1835 [inline] bpf_get_stack_raw_tp+0x1a9/0x220 kernel/trace/bpf_trace.c:1825 bpf_prog_4e330ebee64cb698+0x43/0x4b bpf_dispatcher_nop_func include/linux/bpf.h:1332 [inline] __bpf_prog_run include/linux/filter.h:718 [inline] bpf_prog_run include/linux/filter.h:725 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2257 [inline] bpf_trace_run10+0x2e4/0x500 kernel/trace/bpf_trace.c:2306 __bpf_trace_percpu_alloc_percpu+0x364/0x400 include/trace/events/percpu.h:11 __do_trace_percpu_alloc_percpu include/trace/events/percpu.h:11 [inline] trace_percpu_alloc_percpu include/trace/events/percpu.h:11 [inline] pcpu_alloc_noprof+0x1534/0x16b0 mm/percpu.c:1892 fib_nh_common_init+0x9c/0x3b0 net/ipv4/fib_semantics.c:620 fib6_nh_init+0x1608/0x1ff0 net/ipv6/route.c:3671 ip6_route_info_create_nh+0x16a/0xab0 net/ipv6/route.c:3892 ip6_route_add+0x6e/0x1b0 net/ipv6/route.c:3944 addrconf_add_mroute net/ipv6/addrconf.c:2552 [inline] addrconf_add_dev+0x24f/0x340 net/ipv6/addrconf.c:2570 addrconf_dev_config net/ipv6/addrconf.c:3479 [inline] addrconf_init_auto_addrs+0x57c/0xa30 net/ipv6/addrconf.c:3567 addrconf_notify+0xacc/0x1010 net/ipv6/addrconf.c:3740 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] __dev_notify_flags+0x18d/0x2e0 net/core/dev.c:-1 netif_change_flags+0xe8/0x1a0 net/core/dev.c:9608 do_setlink+0xc55/0x41c0 net/core/rtnetlink.c:3143 rtnl_changelink net/core/rtnetlink.c:3761 [inline] __rtnl_newlink net/core/rtnetlink.c:3920 [inline] rtnl_newlink+0x160b/0x1c70 net/core/rtnetlink.c:4057 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6946 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:729 __sys_sendto+0x3bd/0x520 net/socket.c:2228 __do_sys_sendto net/socket.c:2235 [inline] __se_sys_sendto net/socket.c:2231 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2231 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fec5c790a7c Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b RSP: 002b:00007fff7b55f7b0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fec5d4e35c0 RCX: 00007fec5c790a7c RDX: 0000000000000030 RSI: 00007fec5d4e3610 RDI: 0000000000000006 RBP: 0000000000000000 R08: 00007fff7b55f804 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000006 R13: 0000000000000000 R14: 00007fec5d4e3610 R15: 0000000000000000 </TASK> The buggy address belongs to stack of task syz-executor/5952 and is located at offset 296 in frame: __bpf_get_stack+0x0/0xa70 include/linux/mmap_lock.h:-1 This frame has 1 object: [32, 36) 'rctx.i' The buggy address belongs to a 8-page vmalloc region starting at 0xffffc90003650000 allocated at copy_process+0x54b/0x3c00 kernel/fork.c:2002 The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888024c63200 pfn:0x24c62 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000 raw: ffff888024c63200 0000000000000000 00000001ffffffff 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 0x2dc2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_ZERO|__GFP_NOWARN), pid 5845, tgid 5845 (syz-executor), ts 59049058263, free_ts 59031992240 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline] alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2507 vm_area_alloc_pages mm/vmalloc.c:3642 [inline] __vmalloc_area_node mm/vmalloc.c:3720 [inline] __vmalloc_node_range_noprof+0x97d/0x12f0 mm/vmalloc.c:3893 __vmalloc_node_noprof+0xc2/0x110 mm/vmalloc.c:3956 alloc_thread_stack_node kernel/fork.c:318 [inline] dup_task_struct+0x3e7/0x860 kernel/fork.c:879 copy_process+0x54b/0x3c00 kernel/fork.c:2002 kernel_clone+0x21e/0x840 kernel/fork.c:2603 __do_sys_clone3 kernel/fork.c:2907 [inline] __se_sys_clone3+0x256/0x2d0 kernel/fork.c:2886 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 5907 tgid 5907 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895 vfree+0x25a/0x400 mm/vmalloc.c:3434 kcov_put kernel/kcov.c:439 [inline] kcov_close+0x28/0x50 kernel/kcov.c:535 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:966 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffffc90003655e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffc90003655e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffffc90003655f00: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2 ^ ffffc90003655f80: 00 00 00 00 00 00 00 00 00 00 f3 f3 f3 f3 f3 f3 ffffc90003656000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== *** PANIC: double fault in its_return_thunk tree: bpf-next URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/bpf/bpf-next.git base: f3af62b6cee8af9f07012051874af2d2a451f0e5 arch: amd64 compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 config: https://ci.syzbot.org/builds/5e5c6698-7b84-4bf2-a1ee-1b6223c8d4c3/config C repro: https://ci.syzbot.org/findings/1bf5dce6-467f-4bcd-9357-2726101d2ad1/c_repro syz repro: https://ci.syzbot.org/findings/1bf5dce6-467f-4bcd-9357-2726101d2ad1/syz_repro traps: PANIC: double fault, error_code: 0x0 Oops: double fault: 0000 [#1] SMP KASAN PTI CPU: 0 UID: 0 PID: 5789 Comm: syz-executor930 Not tainted 6.16.0-syzkaller-11113-gf3af62b6cee8-dirty #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:412 Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <c3> cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 e9 6b 2b b9 f5 cc RSP: 0018:ffffffffa0000877 EFLAGS: 00010246 RAX: 2161df6de464b300 RBX: 4800be48c0315641 RCX: 2161df6de464b300 RDX: 0000000000000000 RSI: ffffffff8dba01ee RDI: ffff888105cc9cc0 RBP: eb7a3aa9e9c95e41 R08: ffffffff81000130 R09: ffffffff81000130 R10: ffffffff81d017ac R11: ffffffff8b7707da R12: 3145ffff888028c3 R13: ee8948f875894cf6 R14: 000002baf8c68348 R15: e1cb3861e8c93100 FS: 0000555557cbc380(0000) GS:ffff8880b862a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffa0000868 CR3: 0000000028468000 CR4: 00000000000006f0 Call Trace: Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:412 Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <c3> cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 e9 6b 2b b9 f5 cc RSP: 0018:ffffffffa0000877 EFLAGS: 00010246 RAX: 2161df6de464b300 RBX: 4800be48c0315641 RCX: 2161df6de464b300 RDX: 0000000000000000 RSI: ffffffff8dba01ee RDI: ffff888105cc9cc0 RBP: eb7a3aa9e9c95e41 R08: ffffffff81000130 R09: ffffffff81000130 R10: ffffffff81d017ac R11: ffffffff8b7707da R12: 3145ffff888028c3 R13: ee8948f875894cf6 R14: 000002baf8c68348 R15: e1cb3861e8c93100 FS: 0000555557cbc380(0000) GS:ffff8880b862a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffa0000868 CR3: 0000000028468000 CR4: 00000000000006f0 ---------------- Code disassembly (best guess): 0: cc int3 1: cc int3 2: cc int3 3: cc int3 4: cc int3 5: cc int3 6: cc int3 7: cc int3 8: cc int3 9: cc int3 a: cc int3 b: cc int3 c: cc int3 d: cc int3 e: cc int3 f: cc int3 10: cc int3 11: cc int3 12: cc int3 13: cc int3 14: cc int3 15: cc int3 16: cc int3 17: cc int3 18: cc int3 19: cc int3 1a: cc int3 1b: cc int3 1c: cc int3 1d: cc int3 1e: cc int3 1f: cc int3 20: cc int3 21: cc int3 22: cc int3 23: cc int3 24: cc int3 25: cc int3 26: cc int3 27: cc int3 28: cc int3 29: cc int3 * 2a: c3 ret <-- trapping instruction 2b: cc int3 2c: 90 nop 2d: 90 nop 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: e9 6b 2b b9 f5 jmp 0xf5b92baa 3f: cc int3 *** If these findings have caused you to resend the series or submit a separate fix, please add the following tag to your commit message: Tested-by: syzbot@xxxxxxxxxxxxxxxxxxxxxxxxx --- This report is generated by a bot. It may contain errors. syzbot ci engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx.
