From 209d5ce787450bcb89223b4605182af0b997011a Mon Sep 17 00:00:00 2001 From: Thomas Bächler Date: Fri, 17 Sep 2010 18:02:09 +0200 Subject: 2.6.35.4-2: Fix x86_64 local root exploit --- PATCHCFG | 8 +- patches/compat-root-exploit.patch | 222 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 229 insertions(+), 1 deletion(-) create mode 100644 patches/compat-root-exploit.patch diff --git a/PATCHCFG b/PATCHCFG index 5557bfb..2a93c11 100644 --- a/PATCHCFG +++ b/PATCHCFG @@ -15,13 +15,19 @@ PATCHES=( # add latest fixes from stable queue, if needed # http://git.kernel.org/?p=linux/kernel/git/stable/stable-queue.git + # Fix local root exploits + # http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff&h=c41d68a513c71e35a14f66d71782d27a79a81ea6 + # http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=36d001c70d8a0144ac1d038f6876c484849a74de + # http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=eefdca043e8391dcd719711716492063030b55ac + compat-root-exploit.patch%1 + # add aufs2 support, in reference to: # http://aufs.sourceforge.net aufs2-base-20100802.patch%1 aufs2-standalone-20100802.patch%1 ) # Name of the resulting patch (will be bzipped afterwards) -PATCHNAME="patch-2.6.35.4-1-ARCH" +PATCHNAME="patch-2.6.35.4-2-ARCH" # Run this before applying patches pre_apply() { diff --git a/patches/compat-root-exploit.patch b/patches/compat-root-exploit.patch new file mode 100644 index 0000000..d686595 --- /dev/null +++ b/patches/compat-root-exploit.patch @@ -0,0 +1,222 @@ +diff --git a/arch/ia64/include/asm/compat.h b/arch/ia64/include/asm/compat.h +index f90edc8..9301a28 100644 +--- a/arch/ia64/include/asm/compat.h ++++ b/arch/ia64/include/asm/compat.h +@@ -199,7 +199,7 @@ ptr_to_compat(void __user *uptr) + } + + static __inline__ void __user * +-compat_alloc_user_space (long len) ++arch_compat_alloc_user_space (long len) + { + struct pt_regs *regs = task_pt_regs(current); + return (void __user *) (((regs->r12 & 0xffffffff) & -16) - len); +diff --git a/arch/mips/include/asm/compat.h b/arch/mips/include/asm/compat.h +index 613f691..dbc5106 100644 +--- a/arch/mips/include/asm/compat.h ++++ b/arch/mips/include/asm/compat.h +@@ -145,7 +145,7 @@ static inline compat_uptr_t ptr_to_compat(void __user *uptr) + return (u32)(unsigned long)uptr; + } + +-static inline void __user *compat_alloc_user_space(long len) ++static inline void __user *arch_compat_alloc_user_space(long len) + { + struct pt_regs *regs = (struct pt_regs *) + ((unsigned long) current_thread_info() + THREAD_SIZE - 32) - 1; +diff --git a/arch/parisc/include/asm/compat.h b/arch/parisc/include/asm/compat.h +index 02b77ba..efa0b60 100644 +--- a/arch/parisc/include/asm/compat.h ++++ b/arch/parisc/include/asm/compat.h +@@ -147,7 +147,7 @@ static inline compat_uptr_t ptr_to_compat(void __user *uptr) + return (u32)(unsigned long)uptr; + } + +-static __inline__ void __user *compat_alloc_user_space(long len) ++static __inline__ void __user *arch_compat_alloc_user_space(long len) + { + struct pt_regs *regs = ¤t->thread.regs; + return (void __user *)regs->gr[30]; +diff --git a/arch/powerpc/include/asm/compat.h b/arch/powerpc/include/asm/compat.h +index 396d21a..a11d4ea 100644 +--- a/arch/powerpc/include/asm/compat.h ++++ b/arch/powerpc/include/asm/compat.h +@@ -134,7 +134,7 @@ static inline compat_uptr_t ptr_to_compat(void __user *uptr) + return (u32)(unsigned long)uptr; + } + +-static inline void __user *compat_alloc_user_space(long len) ++static inline void __user *arch_compat_alloc_user_space(long len) + { + struct pt_regs *regs = current->thread.regs; + unsigned long usp = regs->gpr[1]; +diff --git a/arch/s390/include/asm/compat.h b/arch/s390/include/asm/compat.h +index 104f200..a875c2f 100644 +--- a/arch/s390/include/asm/compat.h ++++ b/arch/s390/include/asm/compat.h +@@ -181,7 +181,7 @@ static inline int is_compat_task(void) + + #endif + +-static inline void __user *compat_alloc_user_space(long len) ++static inline void __user *arch_compat_alloc_user_space(long len) + { + unsigned long stack; + +diff --git a/arch/sparc/include/asm/compat.h b/arch/sparc/include/asm/compat.h +index 5016f76..6f57325 100644 +--- a/arch/sparc/include/asm/compat.h ++++ b/arch/sparc/include/asm/compat.h +@@ -167,7 +167,7 @@ static inline compat_uptr_t ptr_to_compat(void __user *uptr) + return (u32)(unsigned long)uptr; + } + +-static inline void __user *compat_alloc_user_space(long len) ++static inline void __user *arch_compat_alloc_user_space(long len) + { + struct pt_regs *regs = current_thread_info()->kregs; + unsigned long usp = regs->u_regs[UREG_I6]; +diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S +index e790bc1..4f5f71e 100644 +--- a/arch/x86/ia32/ia32entry.S ++++ b/arch/x86/ia32/ia32entry.S +@@ -50,7 +50,12 @@ + /* + * Reload arg registers from stack in case ptrace changed them. + * We don't reload %eax because syscall_trace_enter() returned +- * the value it wants us to use in the table lookup. ++ * the %rax value we should see. Instead, we just truncate that ++ * value to 32 bits again as we did on entry from user mode. ++ * If it's a new value set by user_regset during entry tracing, ++ * this matches the normal truncation of the user-mode value. ++ * If it's -1 to make us punt the syscall, then (u32)-1 is still ++ * an appropriately invalid value. + */ + .macro LOAD_ARGS32 offset, _r9=0 + .if \_r9 +@@ -60,6 +65,7 @@ + movl \offset+48(%rsp),%edx + movl \offset+56(%rsp),%esi + movl \offset+64(%rsp),%edi ++ movl %eax,%eax /* zero extension */ + .endm + + .macro CFI_STARTPROC32 simple +@@ -153,7 +159,7 @@ ENTRY(ia32_sysenter_target) + testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10) + CFI_REMEMBER_STATE + jnz sysenter_tracesys +- cmpl $(IA32_NR_syscalls-1),%eax ++ cmpq $(IA32_NR_syscalls-1),%rax + ja ia32_badsys + sysenter_do_call: + IA32_ARG_FIXUP +@@ -195,7 +201,7 @@ sysexit_from_sys_call: + movl $AUDIT_ARCH_I386,%edi /* 1st arg: audit arch */ + call audit_syscall_entry + movl RAX-ARGOFFSET(%rsp),%eax /* reload syscall number */ +- cmpl $(IA32_NR_syscalls-1),%eax ++ cmpq $(IA32_NR_syscalls-1),%rax + ja ia32_badsys + movl %ebx,%edi /* reload 1st syscall arg */ + movl RCX-ARGOFFSET(%rsp),%esi /* reload 2nd syscall arg */ +@@ -248,7 +254,7 @@ sysenter_tracesys: + call syscall_trace_enter + LOAD_ARGS32 ARGOFFSET /* reload args from stack in case ptrace changed it */ + RESTORE_REST +- cmpl $(IA32_NR_syscalls-1),%eax ++ cmpq $(IA32_NR_syscalls-1),%rax + ja int_ret_from_sys_call /* sysenter_tracesys has set RAX(%rsp) */ + jmp sysenter_do_call + CFI_ENDPROC +@@ -314,7 +320,7 @@ ENTRY(ia32_cstar_target) + testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10) + CFI_REMEMBER_STATE + jnz cstar_tracesys +- cmpl $IA32_NR_syscalls-1,%eax ++ cmpq $IA32_NR_syscalls-1,%rax + ja ia32_badsys + cstar_do_call: + IA32_ARG_FIXUP 1 +@@ -367,7 +373,7 @@ cstar_tracesys: + LOAD_ARGS32 ARGOFFSET, 1 /* reload args from stack in case ptrace changed it */ + RESTORE_REST + xchgl %ebp,%r9d +- cmpl $(IA32_NR_syscalls-1),%eax ++ cmpq $(IA32_NR_syscalls-1),%rax + ja int_ret_from_sys_call /* cstar_tracesys has set RAX(%rsp) */ + jmp cstar_do_call + END(ia32_cstar_target) +@@ -425,7 +431,7 @@ ENTRY(ia32_syscall) + orl $TS_COMPAT,TI_status(%r10) + testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%r10) + jnz ia32_tracesys +- cmpl $(IA32_NR_syscalls-1),%eax ++ cmpq $(IA32_NR_syscalls-1),%rax + ja ia32_badsys + ia32_do_call: + IA32_ARG_FIXUP +@@ -444,7 +450,7 @@ ia32_tracesys: + call syscall_trace_enter + LOAD_ARGS32 ARGOFFSET /* reload args from stack in case ptrace changed it */ + RESTORE_REST +- cmpl $(IA32_NR_syscalls-1),%eax ++ cmpq $(IA32_NR_syscalls-1),%rax + ja int_ret_from_sys_call /* ia32_tracesys has set RAX(%rsp) */ + jmp ia32_do_call + END(ia32_syscall) +diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h +index 306160e..1d9cd27 100644 +--- a/arch/x86/include/asm/compat.h ++++ b/arch/x86/include/asm/compat.h +@@ -205,7 +205,7 @@ static inline compat_uptr_t ptr_to_compat(void __user *uptr) + return (u32)(unsigned long)uptr; + } + +-static inline void __user *compat_alloc_user_space(long len) ++static inline void __user *arch_compat_alloc_user_space(long len) + { + struct pt_regs *regs = task_pt_regs(current); + return (void __user *)regs->sp - len; +diff --git a/include/linux/compat.h b/include/linux/compat.h +index 168f7da..c766441 100644 +--- a/include/linux/compat.h ++++ b/include/linux/compat.h +@@ -360,5 +360,8 @@ extern ssize_t compat_rw_copy_check_uvector(int type, + const struct compat_iovec __user *uvector, unsigned long nr_segs, + unsigned long fast_segs, struct iovec *fast_pointer, + struct iovec **ret_pointer); ++ ++extern void __user *compat_alloc_user_space(unsigned long len); ++ + #endif /* CONFIG_COMPAT */ + #endif /* _LINUX_COMPAT_H */ +diff --git a/kernel/compat.c b/kernel/compat.c +index 5adab05..91b33fb 100644 +--- a/kernel/compat.c ++++ b/kernel/compat.c +@@ -1137,3 +1137,24 @@ compat_sys_sysinfo(struct compat_sysinfo __user *info) + + return 0; + } ++ ++/* ++ * Allocate user-space memory for the duration of a single system call, ++ * in order to marshall parameters inside a compat thunk. ++ */ ++void __user *compat_alloc_user_space(unsigned long len) ++{ ++ void __user *ptr; ++ ++ /* If len would occupy more than half of the entire compat space... */ ++ if (unlikely(len > (((compat_uptr_t)~0) >> 1))) ++ return NULL; ++ ++ ptr = arch_compat_alloc_user_space(len); ++ ++ if (unlikely(!access_ok(VERIFY_WRITE, ptr, len))) ++ return NULL; ++ ++ return ptr; ++} ++EXPORT_SYMBOL_GPL(compat_alloc_user_space); -- cgit v1.2.3-54-g00ecf