From d2d56c5f51028cb9f3d800882eb6f4cbd3f9099f Mon Sep 17 00:00:00 2001
From: Marcel Holtmann <marcel@holtmann.org>
Date: Fri, 17 Aug 2007 21:47:58 +0200
Subject: [PATCH] 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>
---
fs/exec.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/fs/exec.c b/fs/exec.c
index 7bdea7937ee8..ce62f7b65f17 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -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);
--
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