39 lines
1.2 KiB
Diff
39 lines
1.2 KiB
Diff
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From c78e53edb802d04f7e4e070fe8314f2544749e7a Mon Sep 17 00:00:00 2001
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From: Andrew Tridgell <andrew@tridgell.net>
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Date: Tue, 26 Nov 2024 09:16:31 +1100
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Subject: [PATCH 4/4] disallow ../ elements in relpath for secure_relative_open
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---
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syscall.c | 7 +++++++
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1 file changed, 7 insertions(+)
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diff --git a/syscall.c b/syscall.c
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index a4b7f542..47c5ea57 100644
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--- a/syscall.c
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+++ b/syscall.c
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@@ -721,6 +721,8 @@ int do_open_nofollow(const char *pathname, int flags)
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must be a relative path, and the relpath must not contain any
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elements in the path which follow symlinks (ie. like O_NOFOLLOW, but
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applies to all path components, not just the last component)
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+
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+ The relpath must also not contain any ../ elements in the path
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*/
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int secure_relative_open(const char *basedir, const char *relpath, int flags, mode_t mode)
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{
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@@ -729,6 +731,11 @@ int secure_relative_open(const char *basedir, const char *relpath, int flags, mo
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errno = EINVAL;
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return -1;
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}
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+ if (strncmp(relpath, "../", 3) == 0 || strstr(relpath, "/../")) {
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+ // no ../ elements allowed in the relpath
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+ errno = EINVAL;
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+ return -1;
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+ }
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#if !defined(O_NOFOLLOW) || !defined(O_DIRECTORY)
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// really old system, all we can do is live with the risks
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--
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2.34.1
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