Thread (51 messages) 51 messages, 8 authors, 2017-08-01
STALE3269d
Revisions (3)
  1. v3 current
  2. v4 [diff vs current]
  3. v5 [diff vs current]

[PATCH v3 13/15] exec: Consolidate dumpability logic

From: Kees Cook <hidden>
Date: 2017-07-18 22:25:56
Also in: linux-fsdevel, lkml
Subsystem: exec & binfmt api, elf, filesystems (vfs and infrastructure), the rest · Maintainers: Kees Cook, Alexander Viro, Christian Brauner, Linus Torvalds

Since it's already valid to set dumpability in the early part of
setup_new_exec(), we can consolidate the logic into a single place.
The BINPRM_FLAGS_ENFORCE_NONDUMP is set during would_dump() calls
before setup_new_exec(), so its test is safe to move as well.

Signed-off-by: Kees Cook <redacted>
---
 fs/exec.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/fs/exec.c b/fs/exec.c
index 81793a193d92..45418d6ec583 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1353,10 +1353,12 @@ void setup_new_exec(struct linux_binprm * bprm)
 
 	current->sas_ss_sp = current->sas_ss_size = 0;
 
-	if (!bprm->secureexec)
-		set_dumpable(current->mm, SUID_DUMP_USER);
-	else
+	/* Figure out dumpability. */
+	if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP ||
+	    bprm->secureexec)
 		set_dumpable(current->mm, suid_dumpable);
+	else
+		set_dumpable(current->mm, SUID_DUMP_USER);
 
 	arch_setup_new_exec();
 	perf_event_exec();
@@ -1370,9 +1372,6 @@ void setup_new_exec(struct linux_binprm * bprm)
 
 	if (bprm->secureexec) {
 		current->pdeath_signal = 0;
-	} else {
-		if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)
-			set_dumpable(current->mm, suid_dumpable);
 	}
 
 	/* An exec changes our domain. We are no longer part of the thread
-- 
2.7.4

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