Description of problem: 从host主机多次重启VM，kmemleak检测疑似有12处内存泄漏 dmesg日志： [root@VM20210305-16 ~]# dmesg |grep memleak [ 0.000000] Command line: BOOT_IMAGE=(hd0,msdos1)/boot/vmlinuz-5.10.134-12_rc1.an8.x86_64+debug root=UUID=169a0746-c62d-49a2-bd6b-0eaec098d42c ro crashkernel=2G crash_kexec_post_notifiers rhgb slub_debug=FPZU kmemleak=on console=tty0 console=ttyS0,115200 console=ttyAMA0,115200n8 [ 1.624500] Kernel command line: BOOT_IMAGE=(hd0,msdos1)/boot/vmlinuz-5.10.134-12_rc1.an8.x86_64+debug root=UUID=169a0746-c62d-49a2-bd6b-0eaec098d42c ro crashkernel=2G crash_kexec_post_notifiers rhgb slub_debug=FPZU kmemleak=on console=tty0 console=ttyS0,115200 console=ttyAMA0,115200n8 [ 54.179832] kmemleak: Kernel memory leak detector initialized (mem pool available: 14148) [ 54.179841] kmemleak: Automatic memory scanning thread started [ 786.563659] kmemleak: 12 new suspected memory leaks (see /sys/kernel/debug/kmemleak) /sys/kernel/debug/kmemleak日志： [root@VM20210305-16 ~]# cat /sys/kernel/debug/kmemleak unreferenced object 0xffff88812badbe00 (size 512): comm "swapper/0", pid 1, jiffies 4294688037 (age 1776.176s) hex dump (first 32 bytes): 00 c0 dc 06 81 88 ff ff 03 00 00 00 05 00 00 00 ................ 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000600794e5>] kmem_cache_alloc_trace+0x128/0x260 [<00000000442f156a>] selinux_sb_alloc_security+0x44/0x200 [<000000007369f053>] security_sb_alloc+0x3c/0x80 [<000000000f1b150a>] alloc_super+0x17c/0x9f0 [<00000000664da278>] sget_fc+0x113/0x6e0 [<000000008af236a6>] vfs_get_super+0x61/0x2b0 [<00000000a14f5713>] vfs_get_tree+0x86/0x2d0 [<00000000cffb5339>] fc_mount+0xf/0x90 [<000000005c5a2071>] vfs_kern_mount.part.38+0x5c/0x90 [<000000002f43995e>] kern_mount+0x42/0xa0 [<000000009897353a>] init_sel_fs+0x136/0x1ef [<000000007df5d583>] do_one_initcall+0xf9/0x550 [<00000000c86a8540>] kernel_init_freeable+0x672/0x6ed [<00000000a206f47b>] kernel_init+0xc/0x13b [<00000000947b3751>] ret_from_fork+0x1f/0x30 unreferenced object 0xffff8881076b4eb8 (size 8): comm "(journald)", pid 291, jiffies 4294718446 (age 1745.784s) hex dump (first 8 bytes): 01 00 00 00 00 00 00 00 ........ backtrace: [<00000000600794e5>] kmem_cache_alloc_trace+0x128/0x260 [<00000000d66213b7>] selinux_key_alloc+0x4b/0x1b0 [<0000000038c65696>] security_key_alloc+0x4c/0x90 [<000000009308491e>] key_alloc+0x721/0xfc0 [<000000009c322877>] keyring_alloc+0x26/0x70 [<000000007aab0b61>] install_session_keyring_to_cred+0x137/0x1d0 [<00000000cbe564fe>] join_session_keyring+0x1df/0x2c0 [<00000000119fbfec>] keyctl_join_session_keyring+0x5e/0x80 [<0000000023cbc3c8>] do_syscall_64+0x30/0x40 [<00000000e494ebc4>] entry_SYSCALL_64_after_hwframe+0x61/0xc6 unreferenced object 0xffff8881076b4760 (size 8): comm "(journald)", pid 291, jiffies 4294718447 (age 1745.783s) hex dump (first 8 bytes): 01 00 00 00 00 00 00 00 ........ backtrace: [<00000000600794e5>] kmem_cache_alloc_trace+0x128/0x260 [<00000000d66213b7>] selinux_key_alloc+0x4b/0x1b0 [<0000000038c65696>] security_key_alloc+0x4c/0x90 [<000000009308491e>] key_alloc+0x721/0xfc0 [<000000008e995b0f>] key_create_or_update+0x52b/0xa70 [<000000003f235625>] __x64_sys_add_key+0x20d/0x3b0 [<0000000023cbc3c8>] do_syscall_64+0x30/0x40 [<00000000e494ebc4>] entry_SYSCALL_64_after_hwframe+0x61/0xc6 unreferenced object 0xffff888104cb11a8 (size 8): comm "(lymouthd)", pid 401, jiffies 4294730285 (age 1733.964s) hex dump (first 8 bytes): 01 00 00 00 00 00 00 00 ........ backtrace: [<00000000600794e5>] kmem_cache_alloc_trace+0x128/0x260 [<00000000d66213b7>] selinux_key_alloc+0x4b/0x1b0 [<0000000038c65696>] security_key_alloc+0x4c/0x90 [<000000009308491e>] key_alloc+0x721/0xfc0 [<000000009c322877>] keyring_alloc+0x26/0x70 [<000000007aab0b61>] install_session_keyring_to_cred+0x137/0x1d0 [<00000000cbe564fe>] join_session_keyring+0x1df/0x2c0 [<00000000119fbfec>] keyctl_join_session_keyring+0x5e/0x80 [<0000000023cbc3c8>] do_syscall_64+0x30/0x40 [<00000000e494ebc4>] entry_SYSCALL_64_after_hwframe+0x61/0xc6 unreferenced object 0xffff888104cb0d40 (size 8): comm "(lymouthd)", pid 401, jiffies 4294730285 (age 1733.964s) hex dump (first 8 bytes): 01 00 00 00 00 00 00 00 ........ backtrace: [<00000000600794e5>] kmem_cache_alloc_trace+0x128/0x260 [<00000000d66213b7>] selinux_key_alloc+0x4b/0x1b0 [<0000000038c65696>] security_key_alloc+0x4c/0x90 [<000000009308491e>] key_alloc+0x721/0xfc0 [<000000008e995b0f>] key_create_or_update+0x52b/0xa70 [<000000003f235625>] __x64_sys_add_key+0x20d/0x3b0 [<0000000023cbc3c8>] do_syscall_64+0x30/0x40 [<00000000e494ebc4>] entry_SYSCALL_64_after_hwframe+0x61/0xc6 unreferenced object 0xffff88813a02c9e0 (size 32): comm "plymouthd", pid 409, jiffies 4294730348 (age 1733.929s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01 00 00 00 03 00 00 00 18 00 00 00 00 00 00 00 ................ backtrace: [<00000000600794e5>] kmem_cache_alloc_trace+0x128/0x260 [<00000000ffefb509>] selinux_sk_alloc_security+0x7e/0x1c0 [<000000008b3c21b1>] security_sk_alloc+0x4c/0x90 [<00000000a9b75f6b>] sk_prot_alloc+0x7f/0x260 [<00000000e9799949>] sk_alloc+0x35/0xe90 [<000000007e934823>] unix_create1+0x9f/0x530 [<000000001cf5a151>] unix_create+0x127/0x1d0 [<0000000086e6f276>] __sock_create+0x3a8/0x890 [<000000002bebbca9>] __sys_socket+0xcc/0x1a0 [<00000000a06b6cad>] __x64_sys_socket+0x6f/0xb0 [<0000000023cbc3c8>] do_syscall_64+0x30/0x40 [<00000000e494ebc4>] entry_SYSCALL_64_after_hwframe+0x61/0xc6 unreferenced object 0xffff8881386c21c0 (size 32): comm "(ystemctl)", pid 523, jiffies 4294740943 (age 1723.347s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01 00 00 00 01 00 00 00 18 00 00 00 00 00 00 00 ................ backtrace: [<00000000600794e5>] kmem_cache_alloc_trace+0x128/0x260 [<00000000ffefb509>] selinux_sk_alloc_security+0x7e/0x1c0 [<000000008b3c21b1>] security_sk_alloc+0x4c/0x90 [<00000000a9b75f6b>] sk_prot_alloc+0x7f/0x260 [<00000000e9799949>] sk_alloc+0x35/0xe90 [<000000007e934823>] unix_create1+0x9f/0x530 [<000000001cf5a151>] unix_create+0x127/0x1d0 [<0000000086e6f276>] __sock_create+0x3a8/0x890 [<000000002bebbca9>] __sys_socket+0xcc/0x1a0 [<00000000a06b6cad>] __x64_sys_socket+0x6f/0xb0 [<0000000023cbc3c8>] do_syscall_64+0x30/0x40 [<00000000e494ebc4>] entry_SYSCALL_64_after_hwframe+0x61/0xc6 unreferenced object 0xffff8881386c26a0 (size 32): comm "(ystemctl)", pid 523, jiffies 4294740944 (age 1723.346s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01 00 00 00 01 00 00 00 18 00 00 00 00 00 00 00 ................ backtrace: [<00000000600794e5>] kmem_cache_alloc_trace+0x128/0x260 [<00000000ffefb509>] selinux_sk_alloc_security+0x7e/0x1c0 [<000000008b3c21b1>] security_sk_alloc+0x4c/0x90 [<00000000a9b75f6b>] sk_prot_alloc+0x7f/0x260 [<00000000e9799949>] sk_alloc+0x35/0xe90 [<000000007e934823>] unix_create1+0x9f/0x530 [<00000000154b2bfd>] unix_stream_connect+0x1a4/0x1590 [<00000000ed72ef01>] __sys_connect+0xfa/0x130 [<0000000052569bc3>] __x64_sys_connect+0x6f/0xb0 [<0000000023cbc3c8>] do_syscall_64+0x30/0x40 [<00000000e494ebc4>] entry_SYSCALL_64_after_hwframe+0x61/0xc6 unreferenced object 0xffff888107434d40 (size 8): comm "(ystemctl)", pid 523, jiffies 4294740959 (age 1723.331s) hex dump (first 8 bytes): 01 00 00 00 00 00 00 00 ........ backtrace: [<00000000600794e5>] kmem_cache_alloc_trace+0x128/0x260 [<00000000d66213b7>] selinux_key_alloc+0x4b/0x1b0 [<0000000038c65696>] security_key_alloc+0x4c/0x90 [<000000009308491e>] key_alloc+0x721/0xfc0 [<000000009c322877>] keyring_alloc+0x26/0x70 [<000000007aab0b61>] install_session_keyring_to_cred+0x137/0x1d0 [<00000000cbe564fe>] join_session_keyring+0x1df/0x2c0 [<00000000119fbfec>] keyctl_join_session_keyring+0x5e/0x80 [<0000000023cbc3c8>] do_syscall_64+0x30/0x40 [<00000000e494ebc4>] entry_SYSCALL_64_after_hwframe+0x61/0xc6 unreferenced object 0xffff888107435788 (size 8): comm "(ystemctl)", pid 523, jiffies 4294740960 (age 1723.359s) hex dump (first 8 bytes): 01 00 00 00 00 00 00 00 ........ backtrace: [<00000000600794e5>] kmem_cache_alloc_trace+0x128/0x260 [<00000000d66213b7>] selinux_key_alloc+0x4b/0x1b0 [<0000000038c65696>] security_key_alloc+0x4c/0x90 [<000000009308491e>] key_alloc+0x721/0xfc0 [<000000008e995b0f>] key_create_or_update+0x52b/0xa70 [<000000003f235625>] __x64_sys_add_key+0x20d/0x3b0 [<0000000023cbc3c8>] do_syscall_64+0x30/0x40 [<00000000e494ebc4>] entry_SYSCALL_64_after_hwframe+0x61/0xc6 unreferenced object 0xffff88813f4b2360 (size 32): comm "systemctl", pid 523, jiffies 4294741048 (age 1723.271s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01 00 00 00 01 00 00 00 18 00 00 00 00 00 00 00 ................ backtrace: [<00000000600794e5>] kmem_cache_alloc_trace+0x128/0x260 [<00000000ffefb509>] selinux_sk_alloc_security+0x7e/0x1c0 [<000000008b3c21b1>] security_sk_alloc+0x4c/0x90 [<00000000a9b75f6b>] sk_prot_alloc+0x7f/0x260 [<00000000e9799949>] sk_alloc+0x35/0xe90 [<000000007e934823>] unix_create1+0x9f/0x530 [<000000001cf5a151>] unix_create+0x127/0x1d0 [<0000000086e6f276>] __sock_create+0x3a8/0x890 [<000000002bebbca9>] __sys_socket+0xcc/0x1a0 [<00000000a06b6cad>] __x64_sys_socket+0x6f/0xb0 [<0000000023cbc3c8>] do_syscall_64+0x30/0x40 [<00000000e494ebc4>] entry_SYSCALL_64_after_hwframe+0x61/0xc6 unreferenced object 0xffff88813f4b29e0 (size 32): comm "systemctl", pid 523, jiffies 4294741048 (age 1723.271s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 01 00 00 00 01 00 00 00 18 00 00 00 00 00 00 00 ................ backtrace: [<00000000600794e5>] kmem_cache_alloc_trace+0x128/0x260 [<00000000ffefb509>] selinux_sk_alloc_security+0x7e/0x1c0 [<000000008b3c21b1>] security_sk_alloc+0x4c/0x90 [<00000000a9b75f6b>] sk_prot_alloc+0x7f/0x260 [<00000000e9799949>] sk_alloc+0x35/0xe90 [<000000007e934823>] unix_create1+0x9f/0x530 [<00000000154b2bfd>] unix_stream_connect+0x1a4/0x1590 [<00000000ed72ef01>] __sys_connect+0xfa/0x130 [<0000000052569bc3>] __x64_sys_connect+0x6f/0xb0 [<0000000023cbc3c8>] do_syscall_64+0x30/0x40 [<00000000e494ebc4>] entry_SYSCALL_64_after_hwframe+0x61/0xc6 Version-Release number of selected component (if applicable): [root@VM20210305-16 ~]# cat /etc/os-release NAME="Anolis OS" VERSION="8.4" ID="anolis" ID_LIKE="rhel fedora centos" VERSION_ID="8.4" PLATFORM_ID="platform:an8" PRETTY_NAME="Anolis OS 8.4" ANSI_COLOR="0;31" HOME_URL="https://openanolis.cn/" [root@VM20210305-16 ~]# uname -r 5.10.134-12_rc1.an8.x86_64+debug cpu信息： [root@VM20210305-16 ~]# lscpu Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 4 On-line CPU(s) list: 0-3 Thread(s) per core: 2 Core(s) per socket: 1 Socket(s): 2 NUMA node(s): 1 Vendor ID: GenuineIntel BIOS Vendor ID: Alibaba Cloud CPU family: 6 Model: 85 Model name: Intel(R) Xeon(R) Platinum 8269CY CPU @ 2.50GHz BIOS Model name: pc-i440fx-2.1 Stepping: 7 CPU MHz: 2499.998 BogoMIPS: 4999.99 Hypervisor vendor: KVM Virtualization type: full L1d cache: 32K L1i cache: 32K L2 cache: 1024K L3 cache: 36608K NUMA node0 CPU(s): 0-3 Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc cpuid tsc_known_freq pni pclmulqdq monitor ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch cpuid_fault invpcid_single pti ibrs ibpb stibp fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 erms invpcid rtm mpx avx512f avx512dq rdseed adx smap avx512cd avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves avx512_vnni 内存信息： [root@VM20210305-16 ~]# free -h total used free shared buff/cache available Mem: 11Gi 955Mi 9.9Gi 17Mi 463Mi 10Gi Swap: 0B 0B 0B How reproducible: 1、从host主机上多次重启虚机，每次查看dmesg是否包含kmemleak内存泄漏信息 Steps to Reproduce: 1.从host主机上多次重启虚机 2.查看dmesg是否包含kmemleak内存泄漏信息 Actual results: kmemleak检测疑似有12处内存泄漏 Expected results: 无内存泄漏 Additional info:
selinux kmemleak 每个版本都会测出来。 对于 selinux kmemleak，找到 RFC 和 社区的讨论，https://lore.kernel.org/lkml/70f2c67a-eb8a-5c28-9f78-838b397370b3@schaufler-ca.com/T/#mc653cca5cb0a67842ac8c1479701c22adf49fbe0 reviewer 认为 “I think that the trivial memory leak here is inconsequential compared to the overhead you're introducing by leaving the NO_DEL hooks enabled.”，翻译过来就是这里的 kmemleak 是微不足道、无关紧要的，就没有合入这个 patch。 因此我们也暂时先放过 selinux kmemleak。