Re: [bug-bash] The kill test of util-linux fails with bash 5.3

[Chet Ramey]

On 7/23/25 3:18 AM, Dr. Werner Fink wrote:

307827 futex(0x7ff1d2806158, FUTEX_WAKE_PRIVATE, 2147483647) = 0
307827 getresuid([399], [399], [399])   = 0
307827 --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=NULL} ---
307827 +++ killed by SIGSEGV +++

This is just a function to get all the current user and group information.

With `ulimit -c unlimited` I see a core dump of the bash-5.3

#0  0x0000000000000000 in ?? ()
Missing separate debuginfos, use: zypper install 
socket_wrapper-debuginfo-1.5.0-1.1.x86_64 
nss_wrapper-debuginfo-1.1.16-1.3.x86_64 uid_wrapper-debuginfo-1.3.1-1.3.x86_64 
pam_wrapper-debuginfo-1.1.7-1.4.x86_64 libreadline8-debuginfo-8.2.13-2.3.x86_64 
glibc-debuginfo-2.41-3.1.x86_64 libncurses6-debuginfo-6.5.20250712-77.1.x86_64
(gdb) bt
#0  0x0000000000000000 in ?? ()
#1  0x000056477dc724bb in uidget () at 
/home/abuild/rpmbuild/BUILD/bash-5.3.0-build/bash-5.3/shell.c:1322
#2  main (argc=4, argv=0x7ffd55b37c78, env=0x7ffd55b37ca0) at 
/home/abuild/rpmbuild/BUILD/bash-5.3.0-build/bash-5.3/shell.c:424
(gdb) up 1
#1  0x000056477dc724bb in uidget () at 
/home/abuild/rpmbuild/BUILD/bash-5.3.0-build/bash-5.3/shell.c:1322
1322      (void) getresgid (&current_user.gid, &current_user.egid, 
&current_user.savegid);

The line numbers don't exactly match up, but ok. Do we really think libc
is crashing in getresgid()?? This isn't android:

https://lists.gnu.org/archive/html/help-bash/2023-06/msg00117.html

(even though that's a different signal).

Bash-5.2 doesn't use those calls; it uses old-style get[ug]id/gete[ug]id.
That is probably why bash-5.2 works here.

Strange ... AFAICS clone3() is used to spawn the subprocess for the shell

307826 clone3({flags=CLONE_VM|CLONE_VFORK|CLONE_CLEAR_SIGHAND, exit_signal=SIGCHLD, 
stack=0x7f7a0d302000, stack_size=0x9000}, 88 <unfinished ...>

This is a libc fork() wrapper thing.


--
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    c...@case.edu    http://tiswww.cwru.edu/~chet/