Linus, this patch is already commited into -stable 2.6.17.y tree. http://www.kernel.org/git/?p=linux/kernel/git/stable/linux-2.6.17.y.git;a=commit;h=8833ebaa3f4325820fe3338ccf6fae04f6669254 I only incorporated a small compilation fix from Fernando Vazquez <fernando@xxxxxxxxxxxxx>. please, commit it into next 2.6.18-rcX. local DoS with corrupted ELFs This patch prevents cross-region mappings on IA64 and SPARC which could lead to system crash. davem@ confirmed: "This looks fine to me." :) Signed-Off-By: Pavel Emelianov <xemul@xxxxxxxxxx> Signed-Off-By: Kirill Korotaev <dev@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx> --- diff --git a/arch/ia64/kernel/sys_ia64.c b/arch/ia64/kernel/sys_ia64.c index 40722d8..9ef62a3 100644 --- a/arch/ia64/kernel/sys_ia64.c +++ b/arch/ia64/kernel/sys_ia64.c @@ -163,10 +163,25 @@ sys_pipe (void) return retval; } +int ia64_mmap_check(unsigned long addr, unsigned long len, + unsigned long flags) +{ + unsigned long roff; + + /* + * Don't permit mappings into unmapped space, the virtual page table + * of a region, or across a region boundary. Note: RGN_MAP_LIMIT is + * equal to 2^n-PAGE_SIZE (for some integer n <= 61) and len > 0. + */ + roff = REGION_OFFSET(addr); + if ((len > RGN_MAP_LIMIT) || (roff > (RGN_MAP_LIMIT - len))) + return -EINVAL; + return 0; +} + static inline unsigned long do_mmap2 (unsigned long addr, unsigned long len, int prot, int flags, int fd, unsigned long pgoff) { - unsigned long roff; struct file *file = NULL; flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); @@ -188,17 +203,6 @@ do_mmap2 (unsigned long addr, unsigned l goto out; } - /* - * Don't permit mappings into unmapped space, the virtual page table of a region, - * or across a region boundary. Note: RGN_MAP_LIMIT is equal to 2^n-PAGE_SIZE - * (for some integer n <= 61) and len > 0. - */ - roff = REGION_OFFSET(addr); - if ((len > RGN_MAP_LIMIT) || (roff > (RGN_MAP_LIMIT - len))) { - addr = -EINVAL; - goto out; - } - down_write(¤t->mm->mmap_sem); addr = do_mmap_pgoff(file, addr, len, prot, flags, pgoff); up_write(¤t->mm->mmap_sem); diff --git a/arch/sparc/kernel/sys_sparc.c b/arch/sparc/kernel/sys_sparc.c index a41c8a5..94ff58c 100644 --- a/arch/sparc/kernel/sys_sparc.c +++ b/arch/sparc/kernel/sys_sparc.c @@ -219,6 +219,21 @@ out: return err; } +int sparc_mmap_check(unsigned long addr, unsigned long len, unsigned long flags) +{ + if (ARCH_SUN4C_SUN4 && + (len > 0x20000000 || + ((flags & MAP_FIXED) && + addr < 0xe0000000 && addr + len > 0x20000000))) + return -EINVAL; + + /* See asm-sparc/uaccess.h */ + if (len > TASK_SIZE - PAGE_SIZE || addr + len > TASK_SIZE - PAGE_SIZE) + return -EINVAL; + + return 0; +} + /* Linux version of mmap */ static unsigned long do_mmap2(unsigned long addr, unsigned long len, unsigned long prot, unsigned long flags, unsigned long fd, @@ -233,25 +248,13 @@ static unsigned long do_mmap2(unsigned l goto out; } - retval = -EINVAL; len = PAGE_ALIGN(len); - if (ARCH_SUN4C_SUN4 && - (len > 0x20000000 || - ((flags & MAP_FIXED) && - addr < 0xe0000000 && addr + len > 0x20000000))) - goto out_putf; - - /* See asm-sparc/uaccess.h */ - if (len > TASK_SIZE - PAGE_SIZE || addr + len > TASK_SIZE - PAGE_SIZE) - goto out_putf; - flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); down_write(¤t->mm->mmap_sem); retval = do_mmap_pgoff(file, addr, len, prot, flags, pgoff); up_write(¤t->mm->mmap_sem); -out_putf: if (file) fput(file); out: diff --git a/arch/sparc64/kernel/sys_sparc.c b/arch/sparc64/kernel/sys_sparc.c index 054d0ab..bf5f14e 100644 --- a/arch/sparc64/kernel/sys_sparc.c +++ b/arch/sparc64/kernel/sys_sparc.c @@ -548,6 +548,26 @@ asmlinkage long sparc64_personality(unsi return ret; } +int sparc64_mmap_check(unsigned long addr, unsigned long len, + unsigned long flags) +{ + if (test_thread_flag(TIF_32BIT)) { + if (len >= STACK_TOP32) + return -EINVAL; + + if ((flags & MAP_FIXED) && addr > STACK_TOP32 - len) + return -EINVAL; + } else { + if (len >= VA_EXCLUDE_START) + return -EINVAL; + + if ((flags & MAP_FIXED) && invalid_64bit_range(addr, len)) + return -EINVAL; + } + + return 0; +} + /* Linux version of mmap */ asmlinkage unsigned long sys_mmap(unsigned long addr, unsigned long len, unsigned long prot, unsigned long flags, unsigned long fd, @@ -563,27 +583,11 @@ asmlinkage unsigned long sys_mmap(unsign } flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); len = PAGE_ALIGN(len); - retval = -EINVAL; - - if (test_thread_flag(TIF_32BIT)) { - if (len >= STACK_TOP32) - goto out_putf; - - if ((flags & MAP_FIXED) && addr > STACK_TOP32 - len) - goto out_putf; - } else { - if (len >= VA_EXCLUDE_START) - goto out_putf; - - if ((flags & MAP_FIXED) && invalid_64bit_range(addr, len)) - goto out_putf; - } down_write(¤t->mm->mmap_sem); retval = do_mmap(file, addr, len, prot, flags, off); up_write(¤t->mm->mmap_sem); -out_putf: if (file) fput(file); out: diff --git a/include/asm-generic/mman.h b/include/asm-generic/mman.h index 3b41d2b..010ced7 100644 --- a/include/asm-generic/mman.h +++ b/include/asm-generic/mman.h @@ -39,4 +39,10 @@ #define MADV_DOFORK 11 /* do inherit ac #define MAP_ANON MAP_ANONYMOUS #define MAP_FILE 0 +#ifdef __KERNEL__ +#ifndef arch_mmap_check +#define arch_mmap_check(addr, len, flags) (0) +#endif +#endif + #endif diff --git a/include/asm-ia64/mman.h b/include/asm-ia64/mman.h index 6ba179f..a42a3e6 100644 --- a/include/asm-ia64/mman.h +++ b/include/asm-ia64/mman.h @@ -8,6 +8,14 @@ #define _ASM_IA64_MMAN_H * David Mosberger-Tang <davidm@xxxxxxxxxx>, Hewlett-Packard Co */ +#ifdef __KERNEL__ +#define arch_mmap_check ia64_mmap_check +#ifndef __ASSEMBLY__ +int ia64_mmap_check(unsigned long addr, unsigned long len, + unsigned long flags); +#endif +#endif + #include <asm-generic/mman.h> #define MAP_GROWSDOWN 0x00100 /* stack-like segment */ diff --git a/include/asm-sparc/mman.h b/include/asm-sparc/mman.h index 88d1886..cf8e002 100644 --- a/include/asm-sparc/mman.h +++ b/include/asm-sparc/mman.h @@ -2,6 +2,14 @@ #ifndef __SPARC_MMAN_H__ #define __SPARC_MMAN_H__ +#ifdef __KERNEL__ +#define arch_mmap_check sparc_mmap_check +#ifndef __ASSEMBLY__ +int sparc_mmap_check(unsigned long addr, unsigned long len, + unsigned long flags); +#endif +#endif + #include <asm-generic/mman.h> /* SunOS'ified... */ diff --git a/include/asm-sparc64/mman.h b/include/asm-sparc64/mman.h index 6fd878e..900e2ac 100644 --- a/include/asm-sparc64/mman.h +++ b/include/asm-sparc64/mman.h @@ -2,6 +2,14 @@ #ifndef __SPARC64_MMAN_H__ #define __SPARC64_MMAN_H__ +#ifdef __KERNEL__ +#define arch_mmap_check sparc64_mmap_check +#ifndef __ASSEMBLY__ +int sparc64_mmap_check(unsigned long addr, unsigned long len, + unsigned long flags); +#endif +#endif + #include <asm-generic/mman.h> /* SunOS'ified... */ diff --git a/mm/mmap.c b/mm/mmap.c index c1868ec..02ecef8 100644 --- a/mm/mmap.c +++ b/mm/mmap.c@@ -913,6 +913,10 @@ unsigned long do_mmap_pgoff(struct file if (!len)
return -EINVAL; + error = arch_mmap_check(addr, len, flags); + if (error) + return error; + /* Careful about overflows.. */ len = PAGE_ALIGN(len); if (!len || len > TASK_SIZE) @@ -1859,6 +1863,7 @@ unsigned long do_brk(unsigned long addr, unsigned long flags; struct rb_node ** rb_link, * rb_parent; pgoff_t pgoff = addr >> PAGE_SHIFT; + int error; len = PAGE_ALIGN(len); if (!len) @@ -1867,6 +1872,12 @@ unsigned long do_brk(unsigned long addr, if ((addr + len) > TASK_SIZE || (addr + len) < addr) return -EINVAL; + flags = VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags; + + error = arch_mmap_check(addr, len, flags); + if (error) + return error; + /* * mlock MCL_FUTURE? */ @@ -1907,8 +1918,6 @@ unsigned long do_brk(unsigned long addr, if (security_vm_enough_memory(len >> PAGE_SHIFT)) return -ENOMEM; - flags = VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags; - /* Can we just expand an old private anonymous mapping? */ if (vma_merge(mm, prev, addr, addr + len, flags, NULL, NULL, pgoff, NULL)) -- VGER BF report: U 0.5 - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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