The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 793838138c157d4c49f4fb744b170747e3dabf58 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '2023112455-magnify-upturned-8e18@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: 793838138c15 ("prctl: Disable prctl(PR_SET_MDWE) on parisc") 24e41bf8a6b4 ("mm: add a NO_INHERIT flag to the PR_SET_MDWE prctl") 0da668333fb0 ("mm: make PR_MDWE_REFUSE_EXEC_GAIN an unsigned long") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 793838138c157d4c49f4fb744b170747e3dabf58 Mon Sep 17 00:00:00 2001 From: Helge Deller <deller@xxxxxx> Date: Sat, 18 Nov 2023 19:33:35 +0100 Subject: [PATCH] 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@xxxxxx> Co-developed-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Reported-by: Sam James <sam@xxxxxxxxxx> Closes: https://github.com/systemd/systemd/issues/29775 Tested-by: Sam James <sam@xxxxxxxxxx> Link: https://lore.kernel.org/all/875y2jro9a.fsf@xxxxxxxxxx/ Cc: <stable@xxxxxxxxxxxxxxx> # v6.3+ 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 */
