6.6-stable review patch. If anyone has any objections, please let me know.
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From: Helge Deller deller@gmx.de
[ Upstream commit 793838138c157d4c49f4fb744b170747e3dabf58 ]
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+ Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/sys.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/kernel/sys.c b/kernel/sys.c index 4a8073c1b2558..7a4ae6d5aecd5 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -2395,6 +2395,10 @@ 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 */