root@polyu:~# ./repro
[  108.717849] [bash 255] copy_creds get_cred(ffff88800eb76400{1,0})::before
[  108.719556] [bash 255] copy_creds get_cred(ffff88800eb76400{2,0})::after
[  108.721283] [bash 255] copy_process copy_creds::after, cred ffff88800eb76400{2}
[  108.730488] [bash 255] copy_process new pid 262, cred ffff88800eb76400
[  108.741815] [repro 262] commit_creds get_cred(ffff888008f92500{1})::before
[  108.743553] [repro 262] commit_creds put_cred(ffff88800eb76400{4,0})*2::before
[  108.744768] [repro 262] commit_creds put_cred(ffff88800eb76400{2,0})*2::after
[  108.746487] [repro 262] override_creds get_new_cred(ffff888008f92d00{2,1})::after = ffff888008f92500{2,1}
[  108.748023] [repro 262] revert_creds(ffff888008f92500{2,1}) put_cred(ffff888008f92d00{1,1})
[  108.749045] [repro 262] revert_creds destroying cred ffff888008f92d00
[  108.752903] audit: type=1400 audit(1643287749.043:7): avc:  denied  { execmem } for  pid=262 comm="repro" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1
262 262 starting[  120.553570] [repro 262] copy_creds get_cred(ffff88800b698700{1,0})::before
 loop
262 262 f[  120.554682] [repro 262] copy_creds get_cred(ffff88800b698700{2,0})::after
orking
[  120.555735] [repro 262] copy_process copy_creds::after, cred ffff88800b698700{2}
[  120.558128] [repro 262] copy_process new pid 263, cred ffff88800b698700
262 262 forked child 263
[  120.662216] [repro 263] copy_creds get_cred(ffff88800b698700{2,2})*2::before
[  120.664049] [repro 263] copy_creds get_cred(ffff88800b698700{4,4})*2::after
[  120.665813] [repro 263] copy_process copy_creds::after, cred ffff88800b698700{4}
[  120.667871] [repro 263] copy_process new pid 264, cred ffff88800b698700
263 263 created thread
263 264 pipe2
263 264 close_range
262 262 checking leak after executor exited
[  120.903105] [repro 263] exit_creds(ffff88800b698700{104,4},ffff88800b698700{104,4})::before
[  120.904060] [repro 264] exit_creds(ffff88800b698700{78,4},ffff88800b698700{78,4})::before
262 262 forking
[  128.427600] [repro 262] copy_creds get_cred(ffff88800b698300{1,0})::before
[  128.428458] [repro 262] copy_creds get_cred(ffff88800b698300{2,0})::after
[  128.429269] [repro 262] copy_process copy_creds::after, cred ffff88800b698300{2}
[  128.431563] [repro 262] copy_process new pid 265, cred ffff88800b698300
262 262 forked child 265
[  128.535194] [repro 265] copy_creds get_cred(ffff88800b698300{2,2})*2::before
[  128.536340] [repro 265] copy_creds get_cred(ffff88800b698300{4,4})*2::after
[  128.537400] [repro 265] copy_process copy_creds::after, cred ffff88800b698300{4}
[  128.538598] [repro 265] copy_process new pid 266, cred ffff88800b698300
265 265 created thread
265 266 pipe2
265 266 close_range
[  128.583801] [repro 266] exit_creds(ffff88800b698300{134,4},ffff88800b698300{134,4})::before
262 262 checking leak after executor exited
[  128.775845] [repro 265] exit_creds(ffff88800b698300{74,2},ffff88800b698300{74,2})::before
[  131.758920] kmemleak: 18 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
[  140.551595] kmemleak: 18 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
BUG: memory leak
unreferenced object 0xffff88800b698700 (size 192):
  comm "repro", pid 262, jiffies 4294787646 (age 20.204s)
  hex dump (first 32 bytes):
    03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    64 65 73 43 00 00 00 00 00 00 00 00 00 00 00 00  desC............
  backtrace:
    [<00000000d0b0ce3c>] prepare_creds+0x3f/0x7b0
    [<00000000409d7bb6>] copy_creds+0x76/0x23b0
    [<000000008c3d2d3e>] copy_process+0x108c/0x7110
    [<00000000f73b6d16>] kernel_clone+0xe7/0x1050
    [<00000000168fe893>] __do_sys_clone+0xc8/0x110
    [<0000000011203206>] do_syscall_64+0x3b/0x90
    [<000000008b42bdb5>] entry_SYSCALL_64_after_hwframe+0x44/0xae

BUG: memory leak
unreferenced object 0xffff88800bb59ec0 (size 32):
  comm "repro", pid 262, jiffies 4294787646 (age 20.204s)
  hex dump (first 32 bytes):
    01 00 00 00 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  ................
  backtrace:
    [<000000007e9969b4>] __kmalloc+0x166/0x350
    [<00000000b196d2bf>] security_prepare_creds+0x114/0x190
    [<00000000ef40a54c>] prepare_creds+0x56e/0x7b0
    [<00000000409d7bb6>] copy_creds+0x76/0x23b0
    [<000000008c3d2d3e>] copy_process+0x108c/0x7110
    [<00000000f73b6d16>] kernel_clone+0xe7/0x1050
    [<00000000168fe893>] __do_sys_clone+0xc8/0x110
    [<0000000011203206>] do_syscall_64+0x3b/0x90
    [<000000008b42bdb5>] entry_SYSCALL_64_after_hwframe+0x44/0xae

BUG: memory leak
unreferenced object 0xffff888019a8d368 (size 1128):
  comm "repro", pid 264, jiffies 4294787787 (age 20.063s)
  hex dump (first 32 bytes):
    80 11 04 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff  ................
  backtrace:
    [<0000000032cef5b7>] alloc_inode+0x169/0x1e0
    [<00000000ee04cd0c>] new_inode_pseudo+0x14/0xe0
    [<00000000d06e5877>] create_pipe_files+0x4d/0x7d0
    [<00000000a7002122>] __do_pipe_flags+0x41/0x240
    [<000000001fe49485>] do_pipe2+0x77/0x160
    [<00000000a085f08d>] __x64_sys_pipe2+0x50/0x70
    [<0000000011203206>] do_syscall_64+0x3b/0x90
    [<000000008b42bdb5>] entry_SYSCALL_64_after_hwframe+0x44/0xae

BUG: memory leak
unreferenced object 0xffff88800eca8ac8 (size 120):
  comm "repro", pid 264, jiffies 4294787787 (age 20.063s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    68 d3 a8 19 80 88 ff ff e0 8a ca 0e 80 88 ff ff  h...............
  backtrace:
    [<000000001d140849>] security_inode_alloc+0x34/0x160
    [<00000000b9db7b36>] inode_init_always+0x559/0xc90
    [<000000003f9ff8d5>] alloc_inode+0x84/0x1e0
    [<00000000ee04cd0c>] new_inode_pseudo+0x14/0xe0
    [<00000000d06e5877>] create_pipe_files+0x4d/0x7d0
    [<00000000a7002122>] __do_pipe_flags+0x41/0x240
    [<000000001fe49485>] do_pipe2+0x77/0x160
    [<00000000a085f08d>] __x64_sys_pipe2+0x50/0x70
    [<0000000011203206>] do_syscall_64+0x3b/0x90
    [<000000008b42bdb5>] entry_SYSCALL_64_after_hwframe+0x44/0xae

BUG: memory leak
unreferenced object 0xffff888009893000 (size 512):
  comm "repro", pid 264, jiffies 4294787787 (age 20.063s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 ad 4e ad de  .............N..
    ff ff ff ff 00 00 00 00 ff ff ff ff ff ff ff ff  ................
  backtrace:
    [<00000000aecfa795>] kmem_cache_alloc_trace+0x1b1/0x410
    [<00000000ec021576>] alloc_pipe_info+0x104/0x4f0
    [<00000000b8acbae8>] create_pipe_files+0x8d/0x7d0
    [<00000000a7002122>] __do_pipe_flags+0x41/0x240
    [<000000001fe49485>] do_pipe2+0x77/0x160
    [<00000000a085f08d>] __x64_sys_pipe2+0x50/0x70
    [<0000000011203206>] do_syscall_64+0x3b/0x90
    [<000000008b42bdb5>] entry_SYSCALL_64_after_hwframe+0x44/0xae

root@polyu:~# [  140.970484] [repro 262] exit_creds(ffff888008f92500{4,2},ffff888008f92500{4,2})::before
[  140.970595] [swapper/2 0] file_free_rcu destroying cred ffff88800eb76400
[  140.974210] [swapper/2 0] file_free_rcu destroying cred ffff888008f92500