[Alexander Lakhin <exclusion@gmail.com>]

Hello Jeff,

07.01.2026 00:10, Jeff Davis wrote:
> Committed, thank you!

I've discovered that starting from c4ff35f10, the following query:
CREATE COLLATION c (provider = icu, locale = 'icu_something');

makes asan detect (maybe dubious, but still..) stack-buffer-overflow:
==21963==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7ffd386d4e63 at pc 0x650cd7972a76 bp 0x7ffd386d4e00 
sp 0x7ffd386d45a8
...
Address 0x7ffd386d4e63 is located in stack of thread T0 at offset 67 in frame
     #0 0x650cd86962ef in foldcase_options (.../usr/local/pgsql/bin/postgres+0x12322ef) (BuildId: 
e441a9634858193e7358e5901e7948606ff5b1b1)

   This frame has 2 object(s):
     [48, 52) 'status' (line 993)
     [64, 67) 'lang' (line 992) <== Memory access at offset 67 overflows this variable

I use a build made with:
CC=gcc-13 CPPFLAGS="-fsanitize=address" LDFLAGS="-fsanitize=address -static-libasan" ./configure --with-icu ...

Could you please have a look?

Best regards,
Alexander