Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [PATCH timers/core] posix-cpu-timers: Put the task_struct in posix_cpu_timers_create | Date | Wed, 04 Mar 2020 09:56:37 +0100 |
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ebiederm@xmission.com (Eric W. Biederman) writes:
> Qian Cai <cai@lca.pw> writes: >> The recent commit removed put_task_struct() in posix_cpu_timer_del() >> results in many memory leaks like this, >> >> unreferenced object 0xc0000016d9b44480 (size 8192): >> comm "timer_create01", pid 57749, jiffies 4295163733 (age 6159.670s) >> hex dump (first 32 bytes): >> 02 00 00 00 00 00 00 00 10 00 00 00 00 00 00 00 ................ >> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ >> backtrace: >> [<0000000056aca129>] copy_process+0x26c/0x18e0 >> alloc_task_struct_node at kernel/fork.c:169 >> (inlined by) dup_task_struct at kernel/fork.c:877 >> (inlined by) copy_process at kernel/fork.c:1929 >> [<00000000bdbbf9f8>] _do_fork+0xac/0xb20 >> [<00000000dcb1c445>] __do_sys_clone+0x98/0xe0 >> __do_sys_clone at kernel/fork.c:2591 >> [<000000006c059205>] ppc_clone+0x8/0xc >> ppc_clone at arch/powerpc/kernel/entry_64.S:479 >> > > I forgot that get_task_for_clock called by posix_cpu_timer_create > returns a reference to a task_struct. Put that reference > to avoid the leak.
I took the liberty to fold this back into the affected commit and add a comment why this put_task_struct() is actually required.
Thanks,
tglx
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