syzbot


memory leak in prepare_creds (5)

Status: upstream: reported C repro on 2025/11/07 07:29
Subsystems: lsm
[Documentation on labels]
Reported-by: syzbot+099461f8558eb0a1f4f3@syzkaller.appspotmail.com
First crash: 35d, last: 9h01m
Discussions (2)
Title Replies (including bot) Last reply
[PATCH] nfsd: fix memory leak in nfsd_create_serv error paths 3 (3) 2025/11/17 16:15
[syzbot] [lsm?] memory leak in prepare_creds (5) 0 (1) 2025/11/07 07:29
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream memory leak in prepare_creds (3) lsm 3 C 24 1050d 1328d 0/29 auto-obsoleted due to no activity on 2023/05/24 05:02
upstream memory leak in prepare_creds (2) lsm 3 C 2 1629d 1724d 20/29 fixed on 2021/11/10 00:50
upstream memory leak in prepare_creds (4) lsm 3 C 5 703d 802d 0/29 auto-obsoleted due to no activity on 2024/04/17 09:09
upstream memory leak in prepare_creds lsm 3 C 10 1755d 1930d 19/29 fixed on 2021/03/10 01:48

Sample crash report:
2025/12/09 17:48:55 executed programs: 5
BUG: memory leak
unreferenced object 0xffff888104e19900 (size 184):
  comm "syz-executor", pid 5984, jiffies 4294944611
  hex dump (first 32 bytes):
    01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace (crc 3707ce50):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4953 [inline]
    slab_alloc_node mm/slub.c:5258 [inline]
    kmem_cache_alloc_noprof+0x3b4/0x590 mm/slub.c:5265
    prepare_creds+0x22/0x5e0 kernel/cred.c:185
    copy_creds+0x44/0x290 kernel/cred.c:286
    copy_process+0x979/0x2860 kernel/fork.c:2086
    kernel_clone+0x119/0x6c0 kernel/fork.c:2651
    __do_sys_clone+0x7b/0xb0 kernel/fork.c:2792
    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
    do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff88810142cdc0 (size 32):
  comm "syz-executor", pid 5984, jiffies 4294944611
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    f8 12 86 00 81 88 ff ff 00 00 00 00 00 00 00 00  ................
  backtrace (crc f9956722):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4953 [inline]
    slab_alloc_node mm/slub.c:5258 [inline]
    __do_kmalloc_node mm/slub.c:5651 [inline]
    __kmalloc_noprof+0x3e0/0x660 mm/slub.c:5664
    kmalloc_noprof include/linux/slab.h:961 [inline]
    kzalloc_noprof include/linux/slab.h:1094 [inline]
    lsm_blob_alloc+0x4d/0x70 security/security.c:192
    lsm_cred_alloc security/security.c:209 [inline]
    security_prepare_creds+0x2f/0x270 security/security.c:2763
    prepare_creds+0x385/0x5e0 kernel/cred.c:215
    copy_creds+0x44/0x290 kernel/cred.c:286
    copy_process+0x979/0x2860 kernel/fork.c:2086
    kernel_clone+0x119/0x6c0 kernel/fork.c:2651
    __do_sys_clone+0x7b/0xb0 kernel/fork.c:2792
    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
    do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff88810dd64f00 (size 184):
  comm "syz.0.17", pid 6075, jiffies 4294944611
  hex dump (first 32 bytes):
    00 00 00 00 07 00 0e 02 c0 e3 66 85 ff ff ff ff  ..........f.....
    90 f5 cd 27 81 88 ff ff 00 00 00 00 00 00 00 00  ...'............
  backtrace (crc 6c773adb):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4953 [inline]
    slab_alloc_node mm/slub.c:5258 [inline]
    kmem_cache_alloc_noprof+0x3b4/0x590 mm/slub.c:5265
    alloc_empty_file+0x51/0x1a0 fs/file_table.c:237
    alloc_file fs/file_table.c:354 [inline]
    alloc_file_pseudo+0xae/0x140 fs/file_table.c:383
    __shmem_file_setup+0x11a/0x210 mm/shmem.c:5843
    shmem_kernel_file_setup mm/shmem.c:5862 [inline]
    __shmem_zero_setup mm/shmem.c:5902 [inline]
    shmem_zero_setup_desc+0x33/0x90 mm/shmem.c:5933
    mmap_zero_prepare+0x4e/0x60 drivers/char/mem.c:524
    vfs_mmap_prepare include/linux/fs.h:2058 [inline]
    call_mmap_prepare mm/vma.c:2596 [inline]
    __mmap_region+0x8b8/0x13e0 mm/vma.c:2692
    mmap_region+0x19f/0x1e0 mm/vma.c:2786
    do_mmap+0x6a3/0xb60 mm/mmap.c:558
    vm_mmap_pgoff+0x1a6/0x2d0 mm/util.c:581
    ksys_mmap_pgoff+0x233/0x2d0 mm/mmap.c:604
    __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
    __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
    __x64_sys_mmap+0x6f/0xa0 arch/x86/kernel/sys_x86_64.c:82
    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
    do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff88810d4ef668 (size 40):
  comm "syz.0.17", pid 6075, jiffies 4294944611
  hex dump (first 32 bytes):
    ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 f8 12 86 00 81 88 ff ff  ................
  backtrace (crc e7d14241):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4953 [inline]
    slab_alloc_node mm/slub.c:5258 [inline]
    kmem_cache_alloc_noprof+0x3b4/0x590 mm/slub.c:5265
    lsm_file_alloc security/security.c:169 [inline]
    security_file_alloc+0x30/0x240 security/security.c:2380
    init_file+0x3e/0x160 fs/file_table.c:159
    alloc_empty_file+0x6f/0x1a0 fs/file_table.c:241
    alloc_file fs/file_table.c:354 [inline]
    alloc_file_pseudo+0xae/0x140 fs/file_table.c:383
    __shmem_file_setup+0x11a/0x210 mm/shmem.c:5843
    shmem_kernel_file_setup mm/shmem.c:5862 [inline]
    __shmem_zero_setup mm/shmem.c:5902 [inline]
    shmem_zero_setup_desc+0x33/0x90 mm/shmem.c:5933
    mmap_zero_prepare+0x4e/0x60 drivers/char/mem.c:524
    vfs_mmap_prepare include/linux/fs.h:2058 [inline]
    call_mmap_prepare mm/vma.c:2596 [inline]
    __mmap_region+0x8b8/0x13e0 mm/vma.c:2692
    mmap_region+0x19f/0x1e0 mm/vma.c:2786
    do_mmap+0x6a3/0xb60 mm/mmap.c:558
    vm_mmap_pgoff+0x1a6/0x2d0 mm/util.c:581
    ksys_mmap_pgoff+0x233/0x2d0 mm/mmap.c:604
    __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
    __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
    __x64_sys_mmap+0x6f/0xa0 arch/x86/kernel/sys_x86_64.c:82
    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
    do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff88810a12e000 (size 184):
  comm "syz-executor", pid 5984, jiffies 4294944612
  hex dump (first 32 bytes):
    01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace (crc 76f18399):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4953 [inline]
    slab_alloc_node mm/slub.c:5258 [inline]
    kmem_cache_alloc_noprof+0x3b4/0x590 mm/slub.c:5265
    prepare_creds+0x22/0x5e0 kernel/cred.c:185
    copy_creds+0x44/0x290 kernel/cred.c:286
    copy_process+0x979/0x2860 kernel/fork.c:2086
    kernel_clone+0x119/0x6c0 kernel/fork.c:2651
    __do_sys_clone+0x7b/0xb0 kernel/fork.c:2792
    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
    do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff888109b44900 (size 32):
  comm "syz-executor", pid 5984, jiffies 4294944612
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    f8 12 86 00 81 88 ff ff 00 00 00 00 00 00 00 00  ................
  backtrace (crc f9956722):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4953 [inline]
    slab_alloc_node mm/slub.c:5258 [inline]
    __do_kmalloc_node mm/slub.c:5651 [inline]
    __kmalloc_noprof+0x3e0/0x660 mm/slub.c:5664
    kmalloc_noprof include/linux/slab.h:961 [inline]
    kzalloc_noprof include/linux/slab.h:1094 [inline]
    lsm_blob_alloc+0x4d/0x70 security/security.c:192
    lsm_cred_alloc security/security.c:209 [inline]
    security_prepare_creds+0x2f/0x270 security/security.c:2763
    prepare_creds+0x385/0x5e0 kernel/cred.c:215
    copy_creds+0x44/0x290 kernel/cred.c:286
    copy_process+0x979/0x2860 kernel/fork.c:2086
    kernel_clone+0x119/0x6c0 kernel/fork.c:2651
    __do_sys_clone+0x7b/0xb0 kernel/fork.c:2792
    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
    do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

connection error: failed to recv *flatrpc.ExecutorMessageRawT: EOF

Crashes (31):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/09 17:49 upstream cb015814f8b6 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/12/09 16:51 upstream cb015814f8b6 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/12/08 13:03 upstream ba65a4e7120a d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/12/08 12:29 upstream ba65a4e7120a d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/12/07 11:42 upstream cc3ee4ba57b7 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/12/07 10:36 upstream cc3ee4ba57b7 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/12/03 13:46 upstream d61f1cc5db79 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/12/03 12:17 upstream d61f1cc5db79 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/12/03 10:48 upstream d61f1cc5db79 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/12/03 09:14 upstream d61f1cc5db79 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/12/03 08:07 upstream d61f1cc5db79 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/12/03 06:54 upstream d61f1cc5db79 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/12/03 05:42 upstream d61f1cc5db79 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/12/03 05:09 upstream d61f1cc5db79 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/12/01 06:04 upstream e69c7c175115 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/11/26 05:33 upstream 8a2bcda5e139 64219f15 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/11/26 03:53 upstream 8a2bcda5e139 64219f15 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/11/25 13:15 upstream ac3fd01e4c1e 64219f15 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/11/25 12:06 upstream ac3fd01e4c1e 64219f15 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/11/25 11:00 upstream ac3fd01e4c1e 64219f15 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/11/25 09:53 upstream ac3fd01e4c1e 64219f15 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/11/25 08:40 upstream ac3fd01e4c1e 64219f15 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/11/24 09:24 upstream d0e88704d96c 4fb8ef37 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/11/24 08:15 upstream d0e88704d96c 4fb8ef37 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/11/21 13:15 upstream fd95357fd8c6 280ea308 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/11/10 16:53 upstream e9a6fb0bcdd7 4e1406b4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/11/08 05:20 upstream da32d155f4a8 4e1406b4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/11/07 15:13 upstream 4a0c9b339199 4e1406b4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/11/07 06:07 upstream c2c2ccfd4ba7 4e1406b4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/11/04 09:50 upstream 8bb886cb8f3a 686bf657 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
2025/11/07 04:56 upstream c2c2ccfd4ba7 4e1406b4 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in prepare_creds
* Struck through repros no longer work on HEAD.