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pgrep: Do not memleak the contents of proc_t.

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memset()ing task and subtask inside their loops prevents free_acquired()
(in readproc() and readtask()) from free()ing their contents (especially
cmdline and environ).

Our solution is not perfect, because we still memleak the very last
cmdline/environ, but select_procs() is called only once, so this is not
as bad as it sounds.

It would be better to leave subtask in its block and call
free_acquired() after the loop, but this function is static (not
exported).

The only other solution is to use freeproc(), but this means replacing
the stack task/subtask with xcalloc()s, thus changing a lot of code in
pgrep.c (to pointer accesses).

Hence this imperfect solution for now.
This commit is contained in:
Qualys Security Advisory 1970-01-01 00:00:00 +00:00 committed by Craig Small
parent 75bd099420
commit 657053f5d0
1 changed files with 2 additions and 12 deletions
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14
pgrep.c
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@ -483,6 +483,7 @@ static struct el * select_procs (int *num)
{ {
PROCTAB *ptp; PROCTAB *ptp;
proc_t task; proc_t task;
proc_t subtask;
unsigned long long saved_start_time; /* for new/old support */ unsigned long long saved_start_time; /* for new/old support */
pid_t saved_pid = 0; /* for new/old support */ pid_t saved_pid = 0; /* for new/old support */
int matches = 0; int matches = 0;
@ -510,6 +511,7 @@ static struct el * select_procs (int *num)
} }
memset(&task, 0, sizeof (task)); memset(&task, 0, sizeof (task));
memset(&subtask, 0, sizeof (subtask));
while(readproc(ptp, &task)) { while(readproc(ptp, &task)) {
int match = 1; int match = 1;
@ -615,8 +617,6 @@ static struct el * select_procs (int *num)
// argparse time, but a further // argparse time, but a further
// control is free // control is free
if (opt_threads && !i_am_pkill) { if (opt_threads && !i_am_pkill) {
proc_t subtask;
memset(&subtask, 0, sizeof (subtask));
while (readtask(ptp, &task, &subtask)){ while (readtask(ptp, &task, &subtask)){
// don't add redundand tasks // don't add redundand tasks
if (task.XXXID == subtask.XXXID) if (task.XXXID == subtask.XXXID)
@ -635,19 +635,9 @@ static struct el * select_procs (int *num)
} else { } else {
list[matches++].num = subtask.XXXID; list[matches++].num = subtask.XXXID;
} }
memset(&subtask, 0, sizeof (subtask));
} }
} }
} }
memset (&task, 0, sizeof (task));
} }
closeproc (ptp); closeproc (ptp);
*num = matches; *num = matches;