[PATCH v2 2/7] x86/modules: Add rlimit checking for x86 modules
From: rick.p.edgecombe@intel.com (Rick Edgecombe)
Date: 2018-10-12 07:09:39
Also in:
linux-arch, linux-fsdevel, linux-mips, linux-s390, lkml, sparclinux
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
This adds in the rlimit checking for the x86 module allocator. Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> --- arch/x86/include/asm/pgtable_32_types.h | 3 +++ arch/x86/include/asm/pgtable_64_types.h | 2 ++ arch/x86/kernel/module.c | 7 ++++++- 3 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/pgtable_32_types.h b/arch/x86/include/asm/pgtable_32_types.h
index b0bc0fff5f1f..185e382fa8c3 100644
--- a/arch/x86/include/asm/pgtable_32_types.h
+++ b/arch/x86/include/asm/pgtable_32_types.h@@ -68,6 +68,9 @@ extern bool __vmalloc_start_set; /* set once high_memory is set */ #define MODULES_END VMALLOC_END #define MODULES_LEN (MODULES_VADDR - MODULES_END) +/* Half of 128MB vmalloc space */ +#define MODSPACE_LIMIT (1 << 25) + #define MAXMEM (VMALLOC_END - PAGE_OFFSET - __VMALLOC_RESERVE) #endif /* _ASM_X86_PGTABLE_32_DEFS_H */
diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h
index 04edd2d58211..c256931f4667 100644
--- a/arch/x86/include/asm/pgtable_64_types.h
+++ b/arch/x86/include/asm/pgtable_64_types.h@@ -143,6 +143,8 @@ extern unsigned int ptrs_per_p4d; #define MODULES_END _AC(0xffffffffff000000, UL) #define MODULES_LEN (MODULES_END - MODULES_VADDR) +#define MODSPACE_LIMIT (MODULES_LEN / 2) + #define ESPFIX_PGD_ENTRY _AC(-2, UL) #define ESPFIX_BASE_ADDR (ESPFIX_PGD_ENTRY << P4D_SHIFT)
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index f58336af095c..5eb3f9c5a976 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c@@ -84,16 +84,21 @@ void *module_alloc(unsigned long size) if (PAGE_ALIGN(size) > MODULES_LEN) return NULL; + if (check_inc_mod_rlimit(size)) + return NULL; + p = __vmalloc_node_range(size, MODULE_ALIGN, MODULES_VADDR + get_module_load_offset(), MODULES_END, GFP_KERNEL, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE, __builtin_return_address(0)); if (p && (kasan_module_alloc(p, size) < 0)) { - vfree(p); + module_memfree(p); return NULL; } + update_mod_rlimit(p, size); + return p; }
--
2.17.1