diff options
| author | Helge Deller <deller@gmx.de> | 2023-11-18 19:33:35 +0100 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2023-11-18 19:35:31 +0100 |
| commit | 793838138c157d4c49f4fb744b170747e3dabf58 (patch) | |
| tree | 4fe9275c0bbcfd3042b70b1880c9e894aeaa65bf | |
| parent | 6ad6e15a9c46b8f0932cd99724f26f3db4db1cdf (diff) | |
| download | lwn-793838138c157d4c49f4fb744b170747e3dabf58.tar.gz lwn-793838138c157d4c49f4fb744b170747e3dabf58.zip | |
prctl: Disable prctl(PR_SET_MDWE) on parisc
systemd-254 tries to use prctl(PR_SET_MDWE) for it's MemoryDenyWriteExecute
functionality, but fails on parisc which still needs executable stacks in
certain combinations of gcc/glibc/kernel.
Disable prctl(PR_SET_MDWE) by returning -EINVAL for now on parisc, until
userspace has catched up.
Signed-off-by: Helge Deller <deller@gmx.de>
Co-developed-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Sam James <sam@gentoo.org>
Closes: https://github.com/systemd/systemd/issues/29775
Tested-by: Sam James <sam@gentoo.org>
Link: https://lore.kernel.org/all/875y2jro9a.fsf@gentoo.org/
Cc: <stable@vger.kernel.org> # v6.3+
| -rw-r--r-- | kernel/sys.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/sys.c b/kernel/sys.c index 420d9cb9cc8e..e219fcfa112d 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -2394,6 +2394,10 @@ static inline int prctl_set_mdwe(unsigned long bits, unsigned long arg3, if (bits & PR_MDWE_NO_INHERIT && !(bits & PR_MDWE_REFUSE_EXEC_GAIN)) return -EINVAL; + /* PARISC cannot allow mdwe as it needs writable stacks */ + if (IS_ENABLED(CONFIG_PARISC)) + return -EINVAL; + current_bits = get_current_mdwe(); if (current_bits && current_bits != bits) return -EPERM; /* Cannot unset the flags */ |