From: Al Viro <viro@zeniv.linux.org.uk>
To: Bernd Edlinger <bernd.edlinger@hotmail.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Roberto Sassu <roberto.sassu@huaweicloud.com>,
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"Peter Zijlstra (Intel)" <peterz@infradead.org>,
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Eric Dumazet <edumazet@google.com>,
zohar@linux.ibm.com, linux-integrity@vger.kernel.org,
Ryan Lee <ryan.lee@canonical.com>,
apparmor <apparmor@lists.ubuntu.com>
Subject: Re: Are setuid shell scripts safe? (Implied by security_bprm_creds_for_exec)
Date: Thu, 4 Dec 2025 05:49:15 +0000 [thread overview]
Message-ID: <20251204054915.GI1712166@ZenIV> (raw)
In-Reply-To: <GV2PPF74270EBEE90CDCD964F69E806EF58E4D9A@GV2PPF74270EBEE.EURP195.PROD.OUTLOOK.COM>
On Wed, Dec 03, 2025 at 02:16:29PM +0100, Bernd Edlinger wrote:
> Hmm, yes, that looks like an issue.
>
> I would have expected the security engine to look at bprm->filenanme
> especially in the case, when bprm->interp != bprm->filename,
> and check that it is not a sym-link with write-access for the
> current user and of course also that the bprm->file is not a regular file
> which is writable by the current user, if that is the case I would have expected
> the secuity engine to enforce non-new-privs on a SUID executable somehow.
Check that _what_ is not a symlink? And while we are at it, what do write
permissions to any symlinks have to do with anything whatsoever?
next prev parent reply other threads:[~2025-12-04 5:49 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <AM8PR10MB470801D01A0CF24BC32C25E7E40E9@AM8PR10MB4708.EURPRD10.PROD.OUTLOOK.COM>
[not found] ` <AM8PR10MB470875B22B4C08BEAEC3F77FE4169@AM8PR10MB4708.EURPRD10.PROD.OUTLOOK.COM>
[not found] ` <AS8P193MB1285DF698D7524EDE22ABFA1E4A1A@AS8P193MB1285.EURP193.PROD.OUTLOOK.COM>
[not found] ` <AS8P193MB12851AC1F862B97FCE9B3F4FE4AAA@AS8P193MB1285.EURP193.PROD.OUTLOOK.COM>
[not found] ` <AS8P193MB1285FF445694F149B70B21D0E46C2@AS8P193MB1285.EURP193.PROD.OUTLOOK.COM>
[not found] ` <AS8P193MB1285937F9831CECAF2A9EEE2E4752@AS8P193MB1285.EURP193.PROD.OUTLOOK.COM>
[not found] ` <GV2PPF74270EBEEEDE0B9742310DE91E9A7E431A@GV2PPF74270EBEE.EURP195.PROD.OUTLOOK.COM>
[not found] ` <GV2PPF74270EBEE9EF78827D73D3D7212F7E432A@GV2PPF74270EBEE.EURP195.PROD.OUTLOOK.COM>
[not found] ` <GV2PPF74270EBEEE807D016A79FE7A2F463E4D6A@GV2PPF74270EBEE.EURP195.PROD.OUTLOOK.COM>
[not found] ` <87tsyozqdu.fsf@email.froward.int.ebiederm.org>
[not found] ` <87wm3ky5n9.fsf@email.froward.int.ebiederm.org>
[not found] ` <87h5uoxw06.fsf_-_@email.froward.int.ebiederm.org>
2025-11-25 11:55 ` [RFC][PATCH] exec: Move cred computation under exec_update_lock Roberto Sassu
2025-12-01 16:06 ` Are setuid shell scripts safe? (Implied by security_bprm_creds_for_exec) Eric W. Biederman
2025-12-01 16:49 ` Roberto Sassu
2025-12-01 18:53 ` Eric W. Biederman
2025-12-01 21:39 ` David Laight
2025-12-03 13:16 ` Bernd Edlinger
2025-12-04 5:49 ` Al Viro [this message]
2025-12-04 9:32 ` David Laight
2025-12-04 13:03 ` Bernd Edlinger
2025-12-09 12:28 ` Jan Kara
2025-12-04 15:43 ` Stephen Smalley
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