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| author | Jan Beulich <jbeulich@novell.com> | 2006-12-07 02:14:13 +0100 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2006-12-07 02:14:13 +0100 |
| commit | 359ad0d4015a9ab39243f2ebc4eb07915bd618b2 (patch) | |
| tree | 90f05d8d9ab048029bfe1e451a012b4d5896aafe /kernel/unwind.c | |
| parent | eef5e0d185fc049bda11fa14ba286fbd357da896 (diff) | |
| download | kernel-crypto-359ad0d4015a9ab39243f2ebc4eb07915bd618b2.tar.gz kernel-crypto-359ad0d4015a9ab39243f2ebc4eb07915bd618b2.tar.xz kernel-crypto-359ad0d4015a9ab39243f2ebc4eb07915bd618b2.zip | |
[PATCH] unwinder: more sanity checks in Dwarf2 unwinder
Tighten the requirements on both input to and output from the Dwarf2
unwinder.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'kernel/unwind.c')
| -rw-r--r-- | kernel/unwind.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/kernel/unwind.c b/kernel/unwind.c index af48168a3af..7e721f10410 100644 --- a/kernel/unwind.c +++ b/kernel/unwind.c @@ -95,6 +95,7 @@ static const struct { typedef unsigned long uleb128_t; typedef signed long sleb128_t; +#define sleb128abs __builtin_labs static struct unwind_table { struct { @@ -787,7 +788,7 @@ int unwind(struct unwind_frame_info *frame) #define FRAME_REG(r, t) (((t *)frame)[reg_info[r].offs]) const u32 *fde = NULL, *cie = NULL; const u8 *ptr = NULL, *end = NULL; - unsigned long pc = UNW_PC(frame) - frame->call_frame; + unsigned long pc = UNW_PC(frame) - frame->call_frame, sp; unsigned long startLoc = 0, endLoc = 0, cfa; unsigned i; signed ptrType = -1; @@ -936,6 +937,9 @@ int unwind(struct unwind_frame_info *frame) state.dataAlign = get_sleb128(&ptr, end); if (state.codeAlign == 0 || state.dataAlign == 0 || ptr >= end) cie = NULL; + else if (UNW_PC(frame) % state.codeAlign + || UNW_SP(frame) % sleb128abs(state.dataAlign)) + return -EPERM; else { retAddrReg = state.version <= 1 ? *ptr++ : get_uleb128(&ptr, end); /* skip augmentation */ @@ -968,6 +972,8 @@ int unwind(struct unwind_frame_info *frame) #ifdef CONFIG_FRAME_POINTER unsigned long top, bottom; + if ((UNW_SP(frame) | UNW_FP(frame)) % sizeof(unsigned long)) + return -EPERM; top = STACK_TOP(frame->task); bottom = STACK_BOTTOM(frame->task); # if FRAME_RETADDR_OFFSET < 0 @@ -1018,6 +1024,7 @@ int unwind(struct unwind_frame_info *frame) || state.regs[retAddrReg].where == Nowhere || state.cfa.reg >= ARRAY_SIZE(reg_info) || reg_info[state.cfa.reg].width != sizeof(unsigned long) + || FRAME_REG(state.cfa.reg, unsigned long) % sizeof(unsigned long) || state.cfa.offs % sizeof(unsigned long)) return -EIO; /* update frame */ @@ -1038,6 +1045,8 @@ int unwind(struct unwind_frame_info *frame) #else # define CASES CASE(8); CASE(16); CASE(32); CASE(64) #endif + pc = UNW_PC(frame); + sp = UNW_SP(frame); for (i = 0; i < ARRAY_SIZE(state.regs); ++i) { if (REG_INVALID(i)) { if (state.regs[i].where == Nowhere) @@ -1118,6 +1127,11 @@ int unwind(struct unwind_frame_info *frame) } } + if (UNW_PC(frame) % state.codeAlign + || UNW_SP(frame) % sleb128abs(state.dataAlign) + || (pc == UNW_PC(frame) && sp == UNW_SP(frame))) + return -EIO; + return 0; #undef CASES #undef FRAME_REG |