Subject: bug#58042: 29.0.50; ASAN use-after-free in re_match_2_internal

From: Eli Zaretskii <[email-masked]>
Date: Tue, 04 Oct 2022 19:35:30 +0300

> From: Gerd Möllmann <[email-masked]>
> Date: Tue, 04 Oct 2022 16:33:45 +0200
> 
> 0x00011f90d0a1 is located 1953 bytes inside of 8184-byte region [0x00011f90c900,0x00011f90e8f8)
> freed by thread T0 here:
>     #0 0x103332de4 in wrap_free+0x98 (libclang_rt.asan_osx_dynamic.dylib:arm64e+0x3ede4)
>     #1 0x100985df8 in rpl_free free.c:48
>     #2 0x1005b6e7c in lisp_free alloc.c:1038
>     #3 0x1005cba7c in compact_small_strings alloc.c:2191
>     #4 0x1005c9bfc in sweep_strings alloc.c:2072
>     #5 0x1005bcd00 in gc_sweep alloc.c:7397
>     #6 0x1005bae50 in garbage_collect alloc.c:6245
>     #7 0x1005ba36c in maybe_garbage_collect alloc.c:6090
>     #8 0x100650284 in maybe_gc lisp.h:5622
>     #9 0x100648cd4 in Ffuncall eval.c:2972
>     #10 0x10064b9a8 in internal_condition_case_n eval.c:1555
>     #11 0x1000cd964 in safe__call xdisp.c:3026
>     #12 0x1000cdc9c in safe__call1 xdisp.c:3062
>     #13 0x1001d60dc in prepare_menu_bars xdisp.c:13572
>     #14 0x1000f2018 in redisplay_internal xdisp.c:16523
>     #15 0x100108c0c in redisplay xdisp.c:16105
>     #16 0x10088fa44 in -[EmacsView layoutSublayersOfLayer:] nsterm.m:8662
>     #17 0x1900a9624 in CA::Layer::layout_if_needed(CA::Transaction*)+0x224 (QuartzCore:arm64e+0x20624)
>     #18 0x1901f661c in CA::Context::commit_transaction(CA::Transaction*, double, double*)+0x1c0 (QuartzCore:arm64e+0x16d61c)
>     #19 0x19008b4c8 in CA::Transaction::commit()+0x2bc (QuartzCore:arm64e+0x24c8)
>     #20 0x18bee1698 in __62+[CATransaction(NSCATransaction) NS_setFlushesWithDisplayLink]_block_invoke+0x12c (AppKit:arm64e+0x1ac698)
>     #21 0x18c646754 in ___NSRunLoopObserverCreateWithHandler_block_invoke+0x3c (AppKit:arm64e+0x911754)
>     #22 0x1892101a0 in __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__+0x20 (CoreFoundation:arm64e+0x841a0)
>     #23 0x18920fff0 in __CFRunLoopDoObservers+0x24c (CoreFoundation:arm64e+0x83ff0)
>     #24 0x18920f524 in __CFRunLoopRun+0x300 (CoreFoundation:arm64e+0x83524)
>     #25 0x18920ea80 in CFRunLoopRunSpecific+0x254 (CoreFoundation:arm64e+0x82a80)
>     #26 0x191e4e334 in RunCurrentEventLoopInMode+0x120 (HIToolbox:arm64e+0x32334)
>     #27 0x191e4dfc0 in ReceiveNextEventCommon+0x140 (HIToolbox:arm64e+0x31fc0)
>     #28 0x191e4de64 in _BlockUntilNextEventMatchingListInModeWithFilter+0x44 (HIToolbox:arm64e+0x31e64)
>     #29 0x18bd76518 in _DPSNextEvent+0x358 (AppKit:arm64e+0x41518)

Any idea how is the above related to the other two backtraces?  Why
don't I see 'main' at the top of the backtrace here?  Can the
sanitizer be asked to produce more than 30 backtrace frames?