Package: procps
Version: 2:4.0.4-4
Severity: normal
I noticed that w is segfaulting sometimes. Backtracing it showed the
issue. Running `w -hs` crashes. The main function passes NULL utmp entry
together with the systemd session, while later print_from expects to be
able to access the utmp data.
(gdb) r
Starting program: /tmp/procps-4.0.4/src/.libs/w -hs
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Program received signal SIGSEGV, Segmentation fault.
print_host (host=host@entry=0x4c <error: Cannot access memory at address 0x4c>,
len=16, len@entry=256, fromlen=fromlen@entry=16) at src/w.c:112
112 if (*host == '\0') break;
(gdb) bt
#0 print_host (host=host@entry=0x4c <error: Cannot access memory at address
0x4c>, len=16, len@entry=256, fromlen=fromlen@entry=16) at src/w.c:112
#1 0x0000555555557371 in print_from (session=session@entry=0x0, u=u@entry=0x0,
ip_addresses=ip_addresses@entry=0, fromlen=fromlen@entry=16) at src/w.c:264
#2 0x0000555555557e6e in showinfo (session=0x5555555654d0 "1794",
name=name@entry=0x55555555d800 "lumag", u=u@entry=0x0,
formtype=formtype@entry=0, maxcmd=maxcmd@entry=156, from=from@entry=1,
userlen=8, fromlen=16, ip_addresses=0, pids=0) at src/w.c:622
#3 0x000055555555671f in main (argc=<optimized out>, argv=<optimized out>) at
src/w.c:831
(gdb) list src/w.c:831
826 if (!strcmp(name, user))
827
showinfo(sessions_list[i], name, NULL, longform,
828 maxcmd, from,
userlen, fromlen,
829 ip_addresses,
pids);
830 } else {
831 showinfo(sessions_list[i],
name, NULL, longform, maxcmd,
832 from, userlen,
fromlen, ip_addresses, pids);
833 }
834 free(name);
835 free(sessions_list[i]);
(gdb) l src/w.c:264
259 if (len) { /* IP address is non-empty, print it (and
concatenate with display, if present) */
260 fputs(buf, stdout);
261 /* show the display part of the host or IPv6
link addr. interface, if present */
262 print_display_or_interface(u->ut_host,
UT_HOSTSIZE, fromlen - len);
263 } else { /* IP address is empty, print the host instead
*/
264 print_host(u->ut_host, UT_HOSTSIZE, fromlen);
265 }
266 } else { /* -i switch NOT used */
267 print_host(u->ut_host, UT_HOSTSIZE, fromlen);
268 }
-- System Information:
Debian Release: trixie/sid
APT prefers testing
APT policy: (500, 'testing')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 6.6.15-amd64 (SMP w/8 CPU threads; PREEMPT)
Kernel taint flags: TAINT_PROPRIETARY_MODULE, TAINT_OOT_MODULE,
TAINT_UNSIGNED_MODULE
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8),
LANGUAGE=en_GB:en
Shell: /bin/sh linked to /usr/bin/bash
Init: systemd (via /run/systemd/system)
Versions of packages procps depends on:
ii init-system-helpers 1.66
ii libc6 2.37-15
ii libncursesw6 6.4+20240113-1
ii libproc2-0 2:4.0.4-4
ii libsystemd0 255.4-1
ii libtinfo6 6.4+20240113-1
Versions of packages procps recommends:
ii psmisc 23.7-1
procps suggests no packages.
-- no debconf information
