Messages in this thread | ![/](/images/icornerl.gif) | | From | Chenyuan Yang <> | Date | Wed, 24 Jan 2024 10:22:48 -0600 | Subject | [Linux Kernel Bug] memory leak in posix_clock_open |
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Dear Linux Developers for Posix Timer,
We encountered "memory leak in posix_clock_open" when testing the posix timer with Syzkaller and our generated specifications.
``` BUG: memory leak unreferenced object 0xffff888000f66fa0 (size 16): comm "syz-executor.0", pid 21073, jiffies 4295079945 (age 8.800s) hex dump (first 16 bytes): 00 b8 d6 0d 80 88 ff ff 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff8162788a>] kmemleak_alloc_recursive include/linux/kmemleak.h:42 [inline] [<ffffffff8162788a>] slab_post_alloc_hook mm/slab.h:766 [inline] [<ffffffff8162788a>] slab_alloc_node mm/slub.c:3478 [inline] [<ffffffff8162788a>] __kmem_cache_alloc_node+0x2fa/0x3e0 mm/slub.c:3517 [<ffffffff81572354>] kmalloc_trace+0x24/0x90 mm/slab_common.c:1098 [<ffffffff81388b0e>] kmalloc include/linux/slab.h:600 [inline] [<ffffffff81388b0e>] kzalloc include/linux/slab.h:721 [inline] [<ffffffff81388b0e>] posix_clock_open+0x5e/0xe0 kernel/time/posix-clock.c:126 [<ffffffff81692d69>] chrdev_open+0x119/0x340 fs/char_dev.c:414 [<ffffffff81680706>] do_dentry_open+0x336/0x9e0 fs/open.c:948 [<ffffffff816a9659>] do_open fs/namei.c:3622 [inline] [<ffffffff816a9659>] path_openat+0x1799/0x1b00 fs/namei.c:3779 [<ffffffff816aa5ce>] do_filp_open+0xce/0x1b0 fs/namei.c:3809 [<ffffffff816843ed>] do_sys_openat2+0xdd/0x130 fs/open.c:1440 [<ffffffff81684d53>] do_sys_open fs/open.c:1455 [inline] [<ffffffff81684d53>] __do_sys_openat fs/open.c:1471 [inline] [<ffffffff81684d53>] __se_sys_openat fs/open.c:1466 [inline] [<ffffffff81684d53>] __x64_sys_openat+0x83/0xe0 fs/open.c:1466 [<ffffffff84ae676f>] do_syscall_x64 arch/x86/entry/common.c:51 [inline] [<ffffffff84ae676f>] do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82 [<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0x6b
BUG: leak checking failed ``` I have attached the reproducible C program and its configuration for this crash. Please note that the C program has not been minimized because there were issues with syz-repro.
For this memory leak, it seems that the `pccontext` allocated by kzalloc (https://elixir.bootlin.com/linux/v6.7/source/kernel/time/posix-clock.c#L126) is not released correctly.
If you have any questions or require more information, please feel free to contact us.
Reported-by: Chenyuan Yang <chenyuan0y@gmail.com>
Best, Chenyuan [unhandled content-type:application/octet-stream][unhandled content-type:application/octet-stream][unhandled content-type:application/octet-stream] | ![\](/images/icornerr.gif) |