From 2ebe396046c99ea191a51f24658273fd860b88c4 Mon Sep 17 00:00:00 2001 From: Brian Behlendorf Date: Mon, 28 Sep 2015 09:08:11 -0700 Subject: [PATCH] Fix PAX Patch/Grsec SLAB_USERCOPY panic Support grsecurity/PaX kernel configurations where CONFIG_PAX_USERCOPY_SLABS are enabled. When this kernel option is enabled slabs which are used to copy between user and kernel space must be created with SLAB_USERCOPY. Stock Linux kernels do not have a SLAB_USERCOPY definition so this causes no change in behavior for non-PAX-enabled kernels. Verified-by: Wuffleton Signed-off-by: Brian Behlendorf Issue #2977 Issue #3796 --- module/spl/spl-kmem-cache.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/module/spl/spl-kmem-cache.c b/module/spl/spl-kmem-cache.c index a83c9f3ae8..a7f9ca3a5d 100644 --- a/module/spl/spl-kmem-cache.c +++ b/module/spl/spl-kmem-cache.c @@ -986,13 +986,23 @@ spl_kmem_cache_create(char *name, size_t size, size_t align, if (rc) goto out; } else { + unsigned long slabflags = 0; + if (size > (SPL_MAX_KMEM_ORDER_NR_PAGES * PAGE_SIZE)) { rc = EINVAL; goto out; } +#if defined(SLAB_USERCOPY) + /* + * Required for PAX-enabled kernels if the slab is to be + * used for coping between user and kernel space. + */ + slabflags |= SLAB_USERCOPY; +#endif + skc->skc_linux_cache = kmem_cache_create( - skc->skc_name, size, align, 0, NULL); + skc->skc_name, size, align, slabflags, NULL); if (skc->skc_linux_cache == NULL) { rc = ENOMEM; goto out;