path: root/kernel/exit.c
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authorOleg Nesterov <oleg@tv-sign.ru>2006-10-28 10:38:50 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-10-28 11:30:54 -0700
commit05d5bcd60e8202e5c7b28cf61186043a4d612623 (patch)
tree7dccbeeb9d0b41103d70f89aae5eb6850f2f788c /kernel/exit.c
parentfca178c0c6e8d52a1875be36b070f30884ebfae9 (diff)
[PATCH] bacct_add_tsk: fix unsafe and wrong parent/group_leader dereference
1. ts = timespec_sub(uptime, current->group_leader->start_time); It is possible that current != tsk. Probably it was supposed to be 'tsk->group_leader->start_time. But why we are reading group_leader's start_time ? This accounting is per thread, not per procees, I changed this to 'tsk->start_time. Please corect me. 2. stats->ac_ppid = (tsk->parent) ? tsk->parent->pid : 0; tsk->parent never == NULL, and it is unsafe to dereference it. Both the task and it's parent may exit after the caller unlocks tasklist_lock, the memory could be unmapped (DEBUG_SLAB). (And we should use ->real_parent->tgid in fact). Q: I don't understand the 'if (thread_group_leader(tsk))' check. Why it is needed ? Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Shailabh Nagar <nagar@watson.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Acked-by: Jay Lan <jlan@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/exit.c')
0 files changed, 0 insertions, 0 deletions