Reset current->pdeath_signal on SUID binary execution (d2d56c5f) · Commits · 戴 / test

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

+9 −4

Original line number	Diff line number	Diff line
		@@ -1084,8 +1084,11 @@ 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) \|\|
		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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