From: stsp <stsp2@yandex.ru>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-kernel@vger.kernel.org,
"Stefan Metzmacher" <metze@samba.org>,
"Eric Biederman" <ebiederm@xmission.com>,
"Andy Lutomirski" <luto@kernel.org>,
"Christian Brauner" <brauner@kernel.org>,
"Jan Kara" <jack@suse.cz>, "Jeff Layton" <jlayton@kernel.org>,
"Chuck Lever" <chuck.lever@oracle.com>,
"Alexander Aring" <alex.aring@gmail.com>,
"David Laight" <David.Laight@aculab.com>,
linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Christian Göttsche" <cgzones@googlemail.com>
Subject: Re: [PATCH 2/2] openat2: add OA2_INHERIT_CRED flag
Date: Thu, 25 Apr 2024 12:23:27 +0300 [thread overview]
Message-ID: <7c620151-be12-4580-818e-86e8b7f46e09@yandex.ru> (raw)
In-Reply-To: <20240425023127.GH2118490@ZenIV>
25.04.2024 05:31, Al Viro пишет:
> Incidentally, suppose you have the same process run with stdin opened
> (r/o) by root. F_SETFD it to O_CLOEXEC, then use your open with
> dirfd being 0, pathname - "" and flags - O_RDWR.
I actually checked this with the test-case.
It seems to return ENOENT:
Breakpoint 1, openat2 (dirfd=0, pathname=0x7fffffffdbee "",
how=0x7fffffffd5e0, size=24) at tst.c:13
13 return syscall(SYS_openat2, dirfd, pathname, how, size);
(gdb) fin
Run till exit from #0 openat2 (dirfd=0, pathname=0x7fffffffdbee "",
how=0x7fffffffd5e0, size=24) at tst.c:13
0x000000000040167b in main (argc=3, argv=0x7fffffffd7b8) at tst.c:140
140 fd = openat2(0, efile, &how1, sizeof(how1));
Value returned is $1 = -1
(gdb) list
135 err = fcntl(0, F_SETFD, O_CLOEXEC);
136 if (err) {
137 perror("fcntl(F_SETFD)");
138 return EXIT_FAILURE;
139 }
140 fd = openat2(0, efile, &how1, sizeof(how1));
141 if (fd == -1) {
142 perror("openat2(1)");
143 // return EXIT_FAILURE;
144 } else {
(gdb) p errno
$2 = 2
So it seems the creds can't be stolen
from a non-dir fd, but I wonder why
ENOENT is returned instead of ENOTDIR.
Such ENOENT is not dicumented in a
man page of openat2(), so I guess there
is some problem here even w/o my patch. :)
next prev parent reply other threads:[~2024-04-25 9:23 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-24 10:52 [PATCH v4 0/2] implement OA2_INHERIT_CRED flag for openat2() Stas Sergeev
2024-04-24 10:52 ` [PATCH 1/2] fs: reorganize path_openat() Stas Sergeev
2024-04-25 8:13 ` kernel test robot
2024-04-24 10:52 ` [PATCH 2/2] openat2: add OA2_INHERIT_CRED flag Stas Sergeev
2024-04-25 2:31 ` Al Viro
2024-04-25 7:24 ` stsp
2024-04-25 9:23 ` stsp [this message]
2024-04-25 13:50 ` kernel test robot
2024-04-25 14:02 ` Christian Brauner
2024-04-26 13:36 ` stsp
2024-04-24 16:09 ` [PATCH v4 0/2] implement OA2_INHERIT_CRED flag for openat2() Christian Brauner
2024-04-24 17:50 ` stsp
2024-04-25 9:54 ` Christian Brauner
2024-04-25 10:12 ` stsp
2024-04-25 12:08 ` Christian Brauner
2024-04-25 12:39 ` stsp
-- strict thread matches above, loose matches on Subject: below --
2024-04-23 22:46 [PATCH v3 " Stas Sergeev
2024-04-23 22:46 ` [PATCH 2/2] openat2: add OA2_INHERIT_CRED flag Stas Sergeev
2024-04-23 11:01 [PATCH v2 0/2] implement OA2_INHERIT_CRED flag for openat2() Stas Sergeev
2024-04-23 11:01 ` [PATCH 2/2] openat2: add OA2_INHERIT_CRED flag Stas Sergeev
2024-04-23 10:48 [PATCH v2 0/2] implement OA2_INHERIT_CRED flag for openat2() Stas Sergeev
2024-04-23 10:48 ` [PATCH 2/2] openat2: add OA2_INHERIT_CRED flag Stas Sergeev
[not found] <20240423104002.9012-1-stsp2@yandex.ru>
2024-04-23 10:40 ` Stas Sergeev
2024-04-22 8:45 [PATCH 1/2] fs: reorganize path_openat() Stas Sergeev
2024-04-22 8:45 ` [PATCH 2/2] openat2: add OA2_INHERIT_CRED flag Stas Sergeev
2024-04-22 19:53 ` Stefan Metzmacher
2024-04-22 20:18 ` stsp
2024-04-23 22:59 ` stsp
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