The top frame corresponds to an interceptor function which is a wrapper around recvmsg() in libc. Because we don't instrument libc, we use interceptors to improve the coverage: they tell the tool about the memory accesses in the library functions. Your report is missing the interesting part that contains the info about the origin of the heap buffer passed to recvmsg() - maybe that'll clarify where the problem is. Most often such reports denote real errors in the user code, not the tool itself.
On Mon, Mar 17, 2014 at 9:26 PM, Jeffrey Walton <[email protected]> wrote: > Hi All, > > I need some help interpreting a result. > > In the result below, is the problem in Asan due to frame 0 and > sanitizer_common_interceptors.inc? Or is the problem in > sock_recvmsg_guts at frame 2? > > I'm confused because frame 0 is usually from the target, and not the Asan > tool. > > Thanks in advance. > > ********** > > ==29767==ERROR: AddressSanitizer: heap-buffer-overflow on address > 0x6030000c0ce4 at pc 0x4aafea bp 0x7fff4c426010 sp 0x7fff4c425fc0 > WRITE of size 24 at 0x6030000c0ce4 thread T0 > #0 0x4aafe9 in write_msghdr > /home/jwalton/Desktop/clang-3.4/llvm-3.4/projects/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc:1395 > #1 0x4aafe9 in __interceptor_recvmsg > /home/jwalton/Desktop/clang-3.4/llvm-3.4/projects/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc:1405 > #2 0x2b955a764166 in sock_recvmsg_guts ./Modules/socketmodule.c:2968 > #3 0x2b955a75f856 in sock_recvmsg ./Modules/socketmodule.c:3098 > #4 0x6642ea in ext_do_call ./Python/ceval.c:4548 > #5 0x6642ea in PyEval_EvalFrameEx ./Python/ceval.c:2869 > #6 0x655aab in PyEval_EvalCodeEx ./Python/ceval.c:3578 > #7 0x670ce5 in fast_function ./Python/ceval.c:4334 > #8 0x65fbf8 in call_function ./Python/ceval.c:4252 > ... > > -- > You received this message because you are subscribed to the Google Groups > "address-sanitizer" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. -- Alexander Potapenko Software Engineer Google Moscow -- You received this message because you are subscribed to the Google Groups "address-sanitizer" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
