From 67582e6eef789324b527b4753065aea366145f4e Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 30 Sep 2011 22:10:33 +0100 Subject: [PATCH] i915: out-of-bounds write in calc_live_regs() From a Coverity defect report. src/mesa/drivers/dri/i915/i915_fragprog.c 301 /* 302 * TODO: consider moving this into core 303 */ 304 static bool calc_live_regs( struct i915_fragment_program *p ) 305 { 306 const struct gl_fragment_program *program = &p->FragProg; 307 GLuint regsUsed = 0xffff0000; -> 308 uint8_t live_components[16] = { 0, }; 309 GLint i; 310 311 for (i = program->Base.NumInstructions - 1; i >= 0; i--) { 312 struct prog_instruction *inst = &program->Base.Instructions[i]; 313 int opArgs = _mesa_num_inst_src_regs(inst->Opcode); 314 int a; 315 316 /* Register is written to: unmark as live for this and preceeding ops */ 317 if (inst->DstReg.File == PROGRAM_TEMPORARY) { -> 318 if (inst->DstReg.Index > 16) 319 return false; 320 -> 321 live_components[inst->DstReg.Index] &= ~inst->DstReg.WriteMask; 322 if (live_components[inst->DstReg.Index] == 0) 323 regsUsed &= ~(1 << inst->DstReg.Index); 324 } 325 326 for (a = 0; a < opArgs; a++) { 327 /* Register is read from: mark as live for this and preceeding ops */ 328 if (inst->SrcReg[a].File == PROGRAM_TEMPORARY) { 329 unsigned c; 330 331 if (inst->SrcReg[a].Index > 16) 332 return false; 333 334 regsUsed |= 1 << inst->SrcReg[a].Index; 335 336 for (c = 0; c < 4; c++) { 337 const unsigned field = GET_SWZ(inst->SrcReg[a].Swizzle, c); 338 339 if (field <= SWIZZLE_W) 340 live_components[inst->SrcReg[a].Index] |= (1U << field); 341 } 342 } 343 } 344 345 p->usedRegs[i] = regsUsed; 346 } Reported-by: Vinson Lee Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=40022 Signed-off-by: Chris Wilson --- src/mesa/drivers/dri/i915/i915_fragprog.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/src/mesa/drivers/dri/i915/i915_fragprog.c b/src/mesa/drivers/dri/i915/i915_fragprog.c index d155b85ffca..e155d16b5d1 100644 --- a/src/mesa/drivers/dri/i915/i915_fragprog.c +++ b/src/mesa/drivers/dri/i915/i915_fragprog.c @@ -304,8 +304,8 @@ do { \ static bool calc_live_regs( struct i915_fragment_program *p ) { const struct gl_fragment_program *program = &p->FragProg; - GLuint regsUsed = 0xffff0000; - uint8_t live_components[16] = { 0, }; + GLuint regsUsed = ~((1 << I915_MAX_TEMPORARY) - 1); + uint8_t live_components[I915_MAX_TEMPORARY] = { 0, }; GLint i; for (i = program->Base.NumInstructions - 1; i >= 0; i--) { @@ -315,7 +315,7 @@ static bool calc_live_regs( struct i915_fragment_program *p ) /* Register is written to: unmark as live for this and preceeding ops */ if (inst->DstReg.File == PROGRAM_TEMPORARY) { - if (inst->DstReg.Index > 16) + if (inst->DstReg.Index >= I915_MAX_TEMPORARY) return false; live_components[inst->DstReg.Index] &= ~inst->DstReg.WriteMask; @@ -328,7 +328,7 @@ static bool calc_live_regs( struct i915_fragment_program *p ) if (inst->SrcReg[a].File == PROGRAM_TEMPORARY) { unsigned c; - if (inst->SrcReg[a].Index > 16) + if (inst->SrcReg[a].Index >= I915_MAX_TEMPORARY) return false; regsUsed |= 1 << inst->SrcReg[a].Index; -- 2.30.2