Subject: + coredump-kill-mmf_dumpable-and-mmf_dump_securely.patch added to -mm tree
To: oleg@xxxxxxxxxx,alex.page.kelly@xxxxxxxxx,ebiederm@xxxxxxxxxxxx,josh@xxxxxxxxxxxxxxxx,keescook@xxxxxxxxxxxx,pmatouse@xxxxxxxxxx,segoon@xxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Tue, 19 Nov 2013 14:22:14 -0800
The patch titled
Subject: coredump: kill MMF_DUMPABLE and MMF_DUMP_SECURELY
has been added to the -mm tree. Its filename is
coredump-kill-mmf_dumpable-and-mmf_dump_securely.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/coredump-kill-mmf_dumpable-and-mmf_dump_securely.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/coredump-kill-mmf_dumpable-and-mmf_dump_securely.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Oleg Nesterov <oleg@xxxxxxxxxx>
Subject: coredump: kill MMF_DUMPABLE and MMF_DUMP_SECURELY
Nobody actually needs MMF_DUMPABLE/MMF_DUMP_SECURELY, they are only used
to enforce the encoding of SUID_DUMP_* enum in mm->flags &
MMF_DUMPABLE_MASK.
Now that set_dumpable() updates both bits atomically we can kill them and
simply store the value "as is" in 2 lower bits.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Alex Kelly <alex.page.kelly@xxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
Cc: Petr Matousek <pmatouse@xxxxxxxxxx>
Cc: Vasily Kulikov <segoon@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/exec.c | 21 ++++++---------------
include/linux/sched.h | 4 +---
2 files changed, 7 insertions(+), 18 deletions(-)
diff -puN fs/exec.c~coredump-kill-mmf_dumpable-and-mmf_dump_securely fs/exec.c
--- a/fs/exec.c~coredump-kill-mmf_dumpable-and-mmf_dump_securely
+++ a/fs/exec.c
@@ -1616,33 +1616,24 @@ void set_binfmt(struct linux_binfmt *new
EXPORT_SYMBOL(set_binfmt);
/*
- * set_dumpable converts traditional three-value dumpable to two flags and
- * stores them into mm->flags.
+ * set_dumpable stores three-value SUID_DUMP_* into mm->flags.
*/
void set_dumpable(struct mm_struct *mm, int value)
{
unsigned long old, new;
+ if (WARN_ON((unsigned)value > SUID_DUMP_ROOT))
+ return;
+
do {
old = ACCESS_ONCE(mm->flags);
- new = old & ~MMF_DUMPABLE_MASK;
-
- switch (value) {
- case SUID_DUMP_ROOT:
- new |= (1 << MMF_DUMP_SECURELY);
- case SUID_DUMP_USER:
- new |= (1<< MMF_DUMPABLE);
- }
-
+ new = (old & ~MMF_DUMPABLE_MASK) | value;
} while (cmpxchg(&mm->flags, old, new) != old);
}
int __get_dumpable(unsigned long mm_flags)
{
- int ret;
-
- ret = mm_flags & MMF_DUMPABLE_MASK;
- return (ret > SUID_DUMP_USER) ? SUID_DUMP_ROOT : ret;
+ return mm_flags & MMF_DUMPABLE_MASK;
}
/*
diff -puN include/linux/sched.h~coredump-kill-mmf_dumpable-and-mmf_dump_securely include/linux/sched.h
--- a/include/linux/sched.h~coredump-kill-mmf_dumpable-and-mmf_dump_securely
+++ a/include/linux/sched.h
@@ -336,10 +336,8 @@ extern int get_dumpable(struct mm_struct
#define SUID_DUMP_ROOT 2 /* Dump as root */
/* mm flags */
-/* dumpable bits */
-#define MMF_DUMPABLE 0 /* core dump is permitted */
-#define MMF_DUMP_SECURELY 1 /* core file is readable only by root */
+/* for SUID_DUMP_* above */
#define MMF_DUMPABLE_BITS 2
#define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
origin.patch
autofs4-allow-autofs-to-work-outside-the-initial-pid-namespace.patch
autofs4-translate-pids-to-the-right-namespace-for-the-daemon.patch
coredump-set_dumpable-fix-the-theoretical-race-with-itself.patch
coredump-kill-mmf_dumpable-and-mmf_dump_securely.patch
coredump-make-__get_dumpable-get_dumpable-inline-kill-fs-coredumph.patch
linux-next.patch
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