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authorHelge Deller <deller@gmx.de>2023-11-18 21:33:35 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-12-03 09:33:06 +0300
commit790afa133f890c9dcf46f3476406eb0e2c638634 (patch)
tree596125f367cb8a535b560cdff87ff6acfe0b2b0f
parent2b00d1fd9a40eede0dd38265f839026a4bb2b4b1 (diff)
downloadlinux-790afa133f890c9dcf46f3476406eb0e2c638634.tar.xz
prctl: Disable prctl(PR_SET_MDWE) on parisc
[ 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>
-rw-r--r--kernel/sys.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/sys.c b/kernel/sys.c
index 4a8073c1b255..7a4ae6d5aecd 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 */