Hello, I found a potential bug titled " KASAN: slab-use-after-free Read in perf_uprobe_destroy " with modified syzkaller in the Linux6.12.25(longterm maintenance, last updated on April 25, 2025) If you fix this issue, please add the following tag to the commit: Reported-by: Jianzhou Zhao luckd0g@163.com, xingwei lee xrivendell7@gmail.com, Penglei Jiang superman.xpt@gmail.com The commit of the kernel is : ef4999852d307d38cfdecd91ed6892cc03beb9b8 kernel config: https://syzkaller.appspot.com/text?tag=KernelConfig&x=55f8591b98dd132 compiler: gcc version 11.4.0

I put the reproduction program of this bug at the end of the email.

------------[ cut here ]----------------------------------------- TITLE: KASAN: slab-use-after-free Read in perf_uprobe_destroy ------------[ cut here ]------------ ================================================================== BUG: KASAN: slab-use-after-free in perf_trace_event_close kernel/trace/trace_event_perf.c:190 [inline] BUG: KASAN: slab-use-after-free in perf_uprobe_destroy+0x1d6/0x200 kernel/trace/trace_event_perf.c:344 Read of size 8 at addr ffff888028f59060 by task syz.0.14/12239

CPU: 0 UID: 0 PID: 12239 Comm: syz.0.14 Not tainted 6.12.25 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1b0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc0/0x5e0 mm/kasan/report.c:488 kasan_report+0x93/0xc0 mm/kasan/report.c:601 perf_trace_event_close kernel/trace/trace_event_perf.c:190 [inline] perf_uprobe_destroy+0x1d6/0x200 kernel/trace/trace_event_perf.c:344 __free_event+0x1d9/0x870 kernel/events/core.c:5330 perf_event_alloc kernel/events/core.c:12437 [inline] perf_event_alloc+0x1246/0x37d0 kernel/events/core.c:12210 __do_sys_perf_event_open+0x44c/0x2aa0 kernel/events/core.c:12847 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb0d09ac5ad Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb0d18f5f98 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007fb0d0be5fa0 RCX: 00007fb0d09ac5ad RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000040 RBP: 00007fb0d0a4458e R08: 000000000000000a R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb0d0be5fa0 R15: 00007fb0d18d6000 </TASK>

Allocated by task 12239: kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x1a5/0x3e0 mm/slub.c:4327 kmalloc_noprof include/linux/slab.h:878 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] trace_probe_init+0xbc/0x5f0 kernel/trace/trace_probe.c:2050 alloc_trace_uprobe+0xa5/0x310 kernel/trace/trace_uprobe.c:347 create_local_trace_uprobe+0x10d/0x4c0 kernel/trace/trace_uprobe.c:1643 perf_uprobe_init+0x13a/0x220 kernel/trace/trace_event_perf.c:319 perf_uprobe_event_init+0x103/0x1d0 kernel/events/core.c:10715 perf_try_init_event+0x137/0xd70 kernel/events/core.c:11976 perf_init_event kernel/events/core.c:12064 [inline] perf_event_alloc kernel/events/core.c:12345 [inline] perf_event_alloc+0x101a/0x37d0 kernel/events/core.c:12210 __do_sys_perf_event_open+0x44c/0x2aa0 kernel/events/core.c:12847 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 12239: kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3a/0x60 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x54/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2372 [inline] slab_free mm/slub.c:4611 [inline] kfree+0x14e/0x4a0 mm/slub.c:4759 trace_probe_unlink+0x185/0x200 kernel/trace/trace_probe.c:2016 trace_probe_cleanup+0x168/0x1d0 kernel/trace/trace_probe.c:2034 free_trace_uprobe.part.0+0x1b/0x80 kernel/trace/trace_uprobe.c:371 free_trace_uprobe kernel/trace/trace_uprobe.c:367 [inline] destroy_local_trace_uprobe+0x5d/0x80 kernel/trace/trace_uprobe.c:1682 perf_try_init_event+0x44b/0xd70 kernel/events/core.c:12007 perf_init_event kernel/events/core.c:12064 [inline] perf_event_alloc kernel/events/core.c:12345 [inline] perf_event_alloc+0x101a/0x37d0 kernel/events/core.c:12210 __do_sys_perf_event_open+0x44c/0x2aa0 kernel/events/core.c:12847 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888028f59000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 96 bytes inside of freed 512-byte region [ffff888028f59000, ffff888028f59200)

The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x28f58 head: order:2 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 ffff88801b041c80 ffffea0000a70200 dead000000000002 raw: 0000000000000000 0000000000100010 00000001f5000000 0000000000000000 head: 00fff00000000040 ffff88801b041c80 ffffea0000a70200 dead000000000002 head: 0000000000000000 0000000000100010 00000001f5000000 0000000000000000 head: 00fff00000000002 ffffea0000a3d601 ffffffffffffffff 0000000000000000 head: 0000000000000004 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 9461, tgid 9461 (syz-executor), ts 105252344888, free_ts 105090780548 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook mm/page_alloc.c:1558 [inline] prep_new_page+0x31b/0x3a0 mm/page_alloc.c:1566 get_page_from_freelist+0x19fb/0x33b0 mm/page_alloc.c:3476 __alloc_pages_noprof+0x324/0x6b0 mm/page_alloc.c:4754 alloc_pages_mpol_noprof+0x2ce/0x610 mm/mempolicy.c:2269 alloc_slab_page mm/slub.c:2442 [inline] allocate_slab mm/slub.c:2608 [inline] new_slab+0x253/0x430 mm/slub.c:2662 ___slab_alloc+0xe1c/0x1720 mm/slub.c:3850 __slab_alloc.isra.0+0x56/0xb0 mm/slub.c:3940 __slab_alloc_node mm/slub.c:3993 [inline] slab_alloc_node mm/slub.c:4154 [inline] __kmalloc_cache_noprof+0x37f/0x3e0 mm/slub.c:4322 kmalloc_noprof include/linux/slab.h:878 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] fib6_info_alloc+0xc9/0x290 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x341/0x1610 net/ipv6/route.c:3802 ip6_route_add+0x26/0x160 net/ipv6/route.c:3896 addrconf_prefix_route.isra.0+0x302/0x510 net/ipv6/addrconf.c:2486 inet6_addr_add+0x73a/0xc10 net/ipv6/addrconf.c:3083 inet6_rtm_newaddr+0x116a/0x18b0 net/ipv6/addrconf.c:5068 rtnetlink_rcv_msg+0x3c9/0xfc0 net/core/rtnetlink.c:6678 netlink_rcv_skb+0x165/0x450 net/netlink/af_netlink.c:2537 page last free pid 9499 tgid 9499 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_page+0x799/0x1320 mm/page_alloc.c:2659 __put_partials+0x151/0x170 mm/slub.c:3177 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x50/0x130 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x165/0x1c0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x67/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4117 [inline] slab_alloc_node mm/slub.c:4166 [inline] __kmalloc_cache_noprof+0x12a/0x3e0 mm/slub.c:4322 kmalloc_noprof include/linux/slab.h:878 [inline] call_modprobe kernel/module/kmod.c:84 [inline] __request_module+0x2a2/0x6b0 kernel/module/kmod.c:173 dev_load+0x1ff/0x240 net/core/dev_ioctl.c:645 dev_ioctl+0x518/0x10b0 net/core/dev_ioctl.c:709 sock_do_ioctl+0x1ca/0x260 net/socket.c:1241 sock_ioctl+0x23a/0x6c0 net/socket.c:1346 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x19d/0x210 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address: ffff888028f58f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888028f58f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

ffff888028f59000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

^ ffff888028f59080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888028f59100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== // autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <dirent.h> #include <endian.h> #include <errno.h> #include <fcntl.h> #include <signal.h> #include <stdarg.h> #include <stdbool.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/prctl.h> #include <sys/stat.h> #include <sys/syscall.h> #include <sys/types.h> #include <sys/wait.h> #include <time.h> #include <unistd.h>

static void sleep_ms(uint64_t ms) { usleep(ms * 1000); }

static uint64_t current_time_ms(void) { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts)) exit(1); return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; }

#define BITMASK(bf_off, bf_len) (((1ull << (bf_len)) - 1) << (bf_off)) #define STORE_BY_BITMASK(type, htobe, addr, val, bf_off, bf_len) \ *(type*)(addr) = \ htobe((htobe(*(type*)(addr)) & ~BITMASK((bf_off), (bf_len))) | \ (((type)(val) << (bf_off)) & BITMASK((bf_off), (bf_len))))

static bool write_file(const char* file, const char* what, ...) { char buf[1024]; va_list args; va_start(args, what); vsnprintf(buf, sizeof(buf), what, args); va_end(args); buf[sizeof(buf) - 1] = 0; int len = strlen(buf); int fd = open(file, O_WRONLY | O_CLOEXEC); if (fd == -1) return false; if (write(fd, buf, len) != len) { int err = errno; close(fd); errno = err; return false; } close(fd); return true; }

static void kill_and_wait(int pid, int* status) { kill(-pid, SIGKILL); kill(pid, SIGKILL); for (int i = 0; i < 100; i++) { if (waitpid(-1, status, WNOHANG | __WALL) == pid) return; usleep(1000); } DIR* dir = opendir("/sys/fs/fuse/connections"); if (dir) { for (;;) { struct dirent* ent = readdir(dir); if (!ent) break; if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0) continue; char abort[300]; snprintf(abort, sizeof(abort), "/sys/fs/fuse/connections/%s/abort", ent->d_name); int fd = open(abort, O_WRONLY); if (fd == -1) { continue; } if (write(fd, abort, 1) < 0) { } close(fd); } closedir(dir); } else { } while (waitpid(-1, status, __WALL) != pid) { } }

static void setup_test() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); write_file("/proc/self/oom_score_adj", "1000"); }

static void execute_one(void);

#define WAIT_FLAGS __WALL

static void loop(void) { int iter = 0; for (;; iter++) { int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { setup_test(); execute_one(); exit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { sleep_ms(10); if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; if (current_time_ms() - start < 5000) continue; kill_and_wait(pid, &status); break; } } }

void execute_one(void) { if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } memcpy((void*)0x200000000000, ".pending_reads\000", 15); syscall(__NR_openat, /*fd=*/0xffffff9c, /*file=*/0x200000000000ul, /*flags=O_SYNC|O_NOATIME|O_LARGEFILE|O_CREAT|O_APPEND*/ 0x149440, /*mode=*/0); *(uint32_t*)0x200000000040 = 8; *(uint32_t*)0x200000000044 = 0x80; *(uint8_t*)0x200000000048 = 2; *(uint8_t*)0x200000000049 = 0; *(uint8_t*)0x20000000004a = 0; *(uint8_t*)0x20000000004b = 0; *(uint32_t*)0x20000000004c = 0; *(uint64_t*)0x200000000050 = 0; *(uint64_t*)0x200000000058 = 0x6a484; *(uint64_t*)0x200000000060 = 4; STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 0, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 1, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 2, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 3, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 4, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 5, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 6, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 7, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 8, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 9, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 10, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 11, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 12, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 13, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 14, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 15, 2); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 17, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 18, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 1, 19, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 20, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 21, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 22, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 23, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 24, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 25, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 26, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 27, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 28, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 29, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 30, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 31, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 32, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 33, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 34, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 35, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 36, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 37, 1); STORE_BY_BITMASK(uint64_t, , 0x200000000068, 0, 38, 26); *(uint32_t*)0x200000000070 = 7; *(uint32_t*)0x200000000074 = 0; *(uint64_t*)0x200000000078 = 0x200000000000; *(uint64_t*)0x200000000080 = 0; *(uint64_t*)0x200000000088 = 0; *(uint64_t*)0x200000000090 = 0; *(uint32_t*)0x200000000098 = 0; *(uint32_t*)0x20000000009c = 0; *(uint64_t*)0x2000000000a0 = 0x40000000000000; *(uint32_t*)0x2000000000a8 = 0; *(uint16_t*)0x2000000000ac = 0; *(uint16_t*)0x2000000000ae = 0; *(uint32_t*)0x2000000000b0 = 9; *(uint32_t*)0x2000000000b4 = 0; *(uint64_t*)0x2000000000b8 = 0; syscall(__NR_perf_event_open, /*attr=*/0x200000000040ul, /*pid=*/0, /*cpu=*/0ul, /*group=*/-1, /*flags=PERF_FLAG_FD_CLOEXEC|PERF_FLAG_FD_OUTPUT*/ 0xaul); } int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffffffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000ul, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x200001000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); const char* reason; (void)reason; loop(); return 0; } ===================================================================

I hope it helps. Best regards Jianzhou Zhao