The patch titled
Allow access to /proc/$PID/fd after setuid()
has been removed from the -mm tree. Its filename was
allow-access-to-proc-pid-fd-after-setuid.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: Allow access to /proc/$PID/fd after setuid()
From: Alexey Dobriyan <adobriyan@xxxxxxxxxx>
/proc/$PID/fd has r-x------ permissions, so if process does setuid(), it
will not be able to access /proc/*/fd/. This breaks fstatat() emulation
in glibc.
open("foo", O_RDONLY|O_DIRECTORY) = 4
setuid32(65534) = 0
stat64("/proc/self/fd/4/bar", 0xbfafb298) = -1 EACCES (Permission denied)
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: James Morris <jmorris@xxxxxxxxx>
Cc: Chris Wright <chrisw@xxxxxxxxxxxx>
Cc: Ulrich Drepper <drepper@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-By: Kirill Korotaev <dev@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/base.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff -puN fs/proc/base.c~allow-access-to-proc-pid-fd-after-setuid fs/proc/base.c
--- a/fs/proc/base.c~allow-access-to-proc-pid-fd-after-setuid
+++ a/fs/proc/base.c
@@ -1448,10 +1448,28 @@ static const struct file_operations proc
};
/*
+ * /proc/pid/fd needs a special permission handler so that a process can still
+ * access /proc/self/fd after it has executed a setuid().
+ */
+static int proc_fd_permission(struct inode *inode, int mask,
+ struct nameidata *nd)
+{
+ int rv;
+
+ rv = generic_permission(inode, mask, NULL);
+ if (rv == 0)
+ return 0;
+ if (task_pid(current) == proc_pid(inode))
+ rv = 0;
+ return rv;
+}
+
+/*
* proc directories can do almost nothing..
*/
static const struct inode_operations proc_fd_inode_operations = {
.lookup = proc_lookupfd,
+ .permission = proc_fd_permission,
.setattr = proc_setattr,
};
_
Patches currently in -mm which might be from adobriyan@xxxxxxxxxx are
origin.patch
git-ia64.patch
git-parisc.patch
x86-msr-add-support-for-safe-variants.patch
-
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