Reset current->pdeath_signal on SUID binary execution

This fixes a vulnerability in the "parent process death signal"
implementation discoverd by Wojciech Purczynski of COSEINC PTE Ltd.
and iSEC Security Research.

http://marc.info/?l=bugtraq&m=118711306802632&w=2

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Marcel Holtmann 2007-08-17 21:47:58 +02:00 committed by Linus Torvalds
parent 28e8351ac2
commit d2d56c5f51

View File

@ -1084,9 +1084,12 @@ int flush_old_exec(struct linux_binprm * bprm)
*/
current->mm->task_size = TASK_SIZE;
if (bprm->e_uid != current->euid || bprm->e_gid != current->egid ||
file_permission(bprm->file, MAY_READ) ||
(bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)) {
if (bprm->e_uid != current->euid || bprm->e_gid != current->egid) {
suid_keys(current);
set_dumpable(current->mm, suid_dumpable);
current->pdeath_signal = 0;
} else if (file_permission(bprm->file, MAY_READ) ||
(bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)) {
suid_keys(current);
set_dumpable(current->mm, suid_dumpable);
}
@ -1177,8 +1180,10 @@ void compute_creds(struct linux_binprm *bprm)
{
int unsafe;
if (bprm->e_uid != current->uid)
if (bprm->e_uid != current->uid) {
suid_keys(current);
current->pdeath_signal = 0;
}
exec_keys(current);
task_lock(current);