From b9fc745db833bbf74b4988493b8cd902a84c9415 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Tue, 19 May 2009 13:25:57 -0400 Subject: integrity: path_check update - Add support in ima_path_check() for integrity checking without incrementing the counts. (Required for nfsd.) - rename and export opencount_get to ima_counts_get - replace ima_shm_check calls with ima_counts_get - export ima_path_check Signed-off-by: Mimi Zohar Signed-off-by: James Morris --- mm/shmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm') diff --git a/mm/shmem.c b/mm/shmem.c index b25f95ce3db7..a817f75f1441 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2684,7 +2684,7 @@ int shmem_zero_setup(struct vm_area_struct *vma) if (IS_ERR(file)) return PTR_ERR(file); - ima_shm_check(file); + ima_counts_get(file); if (vma->vm_file) fput(vma->vm_file); vma->vm_file = file; -- cgit v1.2.3 From c9d9ac525a0285a5b5ad9c3f9aa8b7c1753e6121 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Tue, 19 May 2009 13:25:58 -0400 Subject: integrity: move ima_counts_get Based on discussion on lkml (Andrew Morton and Eric Paris), move ima_counts_get down a layer into shmem/hugetlb__file_setup(). Resolves drm shmem_file_setup() usage case as well. HD comment: I still think you're doing this at the wrong level, but recognize that you probably won't be persuaded until a few more users of alloc_file() emerge, all wanting your ima_counts_get(). Resolving GEM's shmem_file_setup() is an improvement, so I'll say Acked-by: Hugh Dickins Signed-off-by: Mimi Zohar Signed-off-by: James Morris --- fs/hugetlbfs/inode.c | 2 ++ ipc/shm.c | 1 - mm/shmem.c | 2 +- 3 files changed, 3 insertions(+), 2 deletions(-) (limited to 'mm') diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 153d9681192b..ccc62de96df8 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -30,6 +30,7 @@ #include #include #include +#include #include @@ -997,6 +998,7 @@ struct file *hugetlb_file_setup(const char *name, size_t size, int acctflag) &hugetlbfs_file_operations); if (!file) goto out_dentry; /* inode is already attached */ + ima_counts_get(file); return file; diff --git a/ipc/shm.c b/ipc/shm.c index 47b464229cd5..560818353599 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -384,7 +384,6 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) error = PTR_ERR(file); if (IS_ERR(file)) goto no_file; - ima_counts_get(file); id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni); if (id < 0) { diff --git a/mm/shmem.c b/mm/shmem.c index a817f75f1441..0132fbd45a23 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2659,6 +2659,7 @@ struct file *shmem_file_setup(char *name, loff_t size, unsigned long flags) if (error) goto close_file; #endif + ima_counts_get(file); return file; close_file: @@ -2684,7 +2685,6 @@ int shmem_zero_setup(struct vm_area_struct *vma) if (IS_ERR(file)) return PTR_ERR(file); - ima_counts_get(file); if (vma->vm_file) fput(vma->vm_file); vma->vm_file = file; -- cgit v1.2.3 From e0a94c2a63f2644826069044649669b5e7ca75d3 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Wed, 3 Jun 2009 16:04:31 -0400 Subject: security: use mmap_min_addr indepedently of security models This patch removes the dependency of mmap_min_addr on CONFIG_SECURITY. It also sets a default mmap_min_addr of 4096. mmapping of addresses below 4096 will only be possible for processes with CAP_SYS_RAWIO. Signed-off-by: Christoph Lameter Acked-by: Eric Paris Looks-ok-by: Linus Torvalds Signed-off-by: James Morris --- include/linux/mm.h | 2 -- include/linux/security.h | 2 ++ kernel/sysctl.c | 2 -- mm/Kconfig | 19 +++++++++++++++++++ mm/mmap.c | 3 +++ security/Kconfig | 22 +--------------------- security/security.c | 3 --- 7 files changed, 25 insertions(+), 28 deletions(-) (limited to 'mm') diff --git a/include/linux/mm.h b/include/linux/mm.h index bff1f0d475c7..0c21af6abffb 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -580,12 +580,10 @@ static inline void set_page_links(struct page *page, enum zone_type zone, */ static inline unsigned long round_hint_to_min(unsigned long hint) { -#ifdef CONFIG_SECURITY hint &= PAGE_MASK; if (((void *)hint != NULL) && (hint < mmap_min_addr)) return PAGE_ALIGN(mmap_min_addr); -#endif return hint; } diff --git a/include/linux/security.h b/include/linux/security.h index d5fd6163606f..5eff459b3833 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -2197,6 +2197,8 @@ static inline int security_file_mmap(struct file *file, unsigned long reqprot, unsigned long addr, unsigned long addr_only) { + if ((addr < mmap_min_addr) && !capable(CAP_SYS_RAWIO)) + return -EACCES; return 0; } diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 149581fb48ab..45bd711a242e 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1237,7 +1237,6 @@ static struct ctl_table vm_table[] = { .strategy = &sysctl_jiffies, }, #endif -#ifdef CONFIG_SECURITY { .ctl_name = CTL_UNNUMBERED, .procname = "mmap_min_addr", @@ -1246,7 +1245,6 @@ static struct ctl_table vm_table[] = { .mode = 0644, .proc_handler = &proc_doulongvec_minmax, }, -#endif #ifdef CONFIG_NUMA { .ctl_name = CTL_UNNUMBERED, diff --git a/mm/Kconfig b/mm/Kconfig index c2b57d81e153..71830ba7b986 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -226,6 +226,25 @@ config HAVE_MLOCKED_PAGE_BIT config MMU_NOTIFIER bool +config DEFAULT_MMAP_MIN_ADDR + int "Low address space to protect from user allocation" + default 4096 + help + This is the portion of low virtual memory which should be protected + from userspace allocation. Keeping a user from writing to low pages + can help reduce the impact of kernel NULL pointer bugs. + + For most ia64, ppc64 and x86 users with lots of address space + a value of 65536 is reasonable and should cause no problems. + On arm and other archs it should not be higher than 32768. + Programs which use vm86 functionality would either need additional + permissions from either the LSM or the capabilities module or have + this protection disabled. + + This value can be changed after boot using the + /proc/sys/vm/mmap_min_addr tunable. + + config NOMMU_INITIAL_TRIM_EXCESS int "Turn on mmap() excess space trimming before booting" depends on !MMU diff --git a/mm/mmap.c b/mm/mmap.c index 6b7b1a95944b..2b43fa1aa3c8 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -87,6 +87,9 @@ int sysctl_overcommit_ratio = 50; /* default is 50% */ int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT; struct percpu_counter vm_committed_as; +/* amount of vm to protect from userspace access */ +unsigned long mmap_min_addr = CONFIG_DEFAULT_MMAP_MIN_ADDR; + /* * Check that a process has enough memory to allocate a new virtual * mapping. 0 means there is enough memory for the allocation to diff --git a/security/Kconfig b/security/Kconfig index bb244774e9d7..d23c839038f0 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -110,28 +110,8 @@ config SECURITY_ROOTPLUG See for more information about this module. - - If you are unsure how to answer this question, answer N. - -config SECURITY_DEFAULT_MMAP_MIN_ADDR - int "Low address space to protect from user allocation" - depends on SECURITY - default 0 - help - This is the portion of low virtual memory which should be protected - from userspace allocation. Keeping a user from writing to low pages - can help reduce the impact of kernel NULL pointer bugs. - - For most ia64, ppc64 and x86 users with lots of address space - a value of 65536 is reasonable and should cause no problems. - On arm and other archs it should not be higher than 32768. - Programs which use vm86 functionality would either need additional - permissions from either the LSM or the capabilities module or have - this protection disabled. - - This value can be changed after boot using the - /proc/sys/vm/mmap_min_addr tunable. + If you are unsure how to answer this question, answer N. source security/selinux/Kconfig source security/smack/Kconfig diff --git a/security/security.c b/security/security.c index 5284255c5cdf..dc7674fbfc7a 100644 --- a/security/security.c +++ b/security/security.c @@ -26,9 +26,6 @@ extern void security_fixup_ops(struct security_operations *ops); struct security_operations *security_ops; /* Initialized to NULL */ -/* amount of vm to protect from userspace access */ -unsigned long mmap_min_addr = CONFIG_SECURITY_DEFAULT_MMAP_MIN_ADDR; - static inline int verify(struct security_operations *ops) { /* verify the security_operations structure exists */ -- cgit v1.2.3 From 35f2c2f6f6ae13ef23c4f68e6d3073753077ca43 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Tue, 9 Jun 2009 17:48:56 +0900 Subject: nommu: Provide mmap_min_addr definition. With the "security: use mmap_min_addr indepedently of security models" change, mmap_min_addr is used in common areas, which susbsequently blows up the nommu build. This stubs in the definition in the nommu case as well. Signed-off-by: Paul Mundt -- mm/nommu.c | 3 +++ 1 file changed, 3 insertions(+) Signed-off-by: James Morris --- mm/nommu.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'mm') diff --git a/mm/nommu.c b/mm/nommu.c index b571ef707428..2fd2ad5da98e 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -69,6 +69,9 @@ int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT; int sysctl_nr_trim_pages = CONFIG_NOMMU_INITIAL_TRIM_EXCESS; int heap_stack_gap = 0; +/* amount of vm to protect from userspace access */ +unsigned long mmap_min_addr = CONFIG_DEFAULT_MMAP_MIN_ADDR; + atomic_long_t mmap_pages_allocated; EXPORT_SYMBOL(mem_map); -- cgit v1.2.3