Re: [PATCH 1/2] gdb: fix possible nullptr dereference in a remote_debug_printf call

Tom Tromey
2023-07-19T15:01:33Z

>>>>> "Andrew" == Andrew Burgess via Gdb-patches <gdb-patches@sourceware.org> writes:

Andrew> While working on the next patch I triggered a segfault from within the
Andrew> function remote_target::discard_pending_stop_replies. Turns out this
Andrew> was caused by a cut&paste error introduced in this commit:

Andrew> commit df5ad102009c41ab4dfadbb8cfb8c8b2a02a4f78
Andrew> Date: Wed Dec 1 09:40:03 2021 -0500

Andrew> gdb, gdbserver: detach fork child when detaching from fork parent

Andrew> This commit adds a remote_debug_printf call that was copied from
Andrew> earlier in the function, however, the new call wasn't updated to use
Andrew> the appropriate local variable. The local variable that it is using
Andrew> might be nullptr, in which case we trigger undefined behaviour, and
Andrew> could crash, which is what I was seeing.

Andrew> Fixed by updating to use the correct local variable.

Seems obvious to me FWIW.

Tom