libsanitizer: Hwasan reporting check for dladdr failing
authorMatthew Malcomson <matthew.malcomson@arm.com>
Wed, 25 Nov 2020 16:31:35 +0000 (16:31 +0000)
committerMatthew Malcomson <matthew.malcomson@arm.com>
Wed, 25 Nov 2020 16:35:31 +0000 (16:35 +0000)
commit8eb12742e8ae5a16e05be627c701234dc7c13504
tree790322638eedb4a867dc18779c490330d982d0fd
parent1ee3d1ef105c5181fbf298b8ddb638f8e3cbaaca
libsanitizer: Hwasan reporting check for dladdr failing

In `GetGlobalSizeFromDescriptor` we use `dladdr` to get info on the the
current address.  `dladdr` returns 0 if it failed.
During testing on Linux this returned 0 to indicate failure, and
populated the `info` structure with a NULL pointer which was
dereferenced later.

This patch checks for `dladdr` returning 0, and in that case returns 0
from `GetGlobalSizeFromDescriptor` to indicate failure of identifying
the address.

This occurs when `GetModuleNameAndOffsetForPC` succeeds for some address
not in a dynamically loaded library.  One example is when the found
"module" is '[stack]' having come from parsing /proc/self/maps.

Cherry-pick from 83ac18205ec69a00ac2be3b603bc3a61293fbe89.

Differential Revision: https://reviews.llvm.org/D91344
libsanitizer/hwasan/hwasan_report.cpp