Bug#946158: lightdm-gtk-greeter or libcairo2 segfault immediately after submitting password, unlocking session
Hello dinar qurbanov,
I am guessing you are using Buster/stable i386?
If reportbug would be used for reporting bugs, such
information gets added automatically to the report.
Then the "Code" in the syslog the crash most probably
happened in _cairo_surface_set_error [1].
Unfortunately I doubt that information is enough for the
maintainer to fix this issue.
If it would be possible to install systemd-coredump,
then a backtrace for each crashing app would be added
to the journal, that could be of help.
And I cannot judge if this could be due to bad sectors on
your disk, therefore at least below the md5sums [2] of the files
I got installed. Maybe you want to lookup smartctl, if your
disk recorded itself some errors.
Kind regards,
Bernhard
[1] https://sources.debian.org/src/cairo/1.16.0-4/src/cairo-surface.c/#L201
[2]
# md5sum /usr/lib/i386-linux-gnu/libcairo.so.2.11600.0
273f0014984b9f43abbed04cd9e0bc0c /usr/lib/i386-linux-gnu/libcairo.so.2.11600.0
# md5sum /usr/sbin/lightdm-gtk-greeter
dbfa2151ff036c85f4659358d7a5f392 /usr/sbin/lightdm-gtk-greeter
# from submitter:
Dec 4 14:28:08 localhost kernel: [ 5707.165413] lightdm-gtk-gre[9162]: segfault at 8 ip b73a92e4 sp bfa6f59c error 4 in libcairo.so.2.11600.0[b733d000+dd000]
Dec 4 14:28:08 localhost kernel: [ 5707.165431] Code: 51 14 89 54 24 04 e9 1b e5 fa ff 8d 76 00 31 c0 c3 8d 74 26 00 90 89 d0 c3 8d b4 26 00 00 00 00 8d b6 00 00 00 00 8b 44 24 04 <8b> 40 08 c3 8d b4 26 00 00 00 00 90 8b 44 24 04 8b 40 0c c3 8d b4
###########
Buster/stable i386 qemu VM 2019-12-07
apt update
apt dist-ugprade
apt install mc gdb lightdm-gtk-greeter lightdm-gtk-greeter-dbgsym libcairo2-dbgsym
gdb -q --args lightdm-gtk-greeter
set width 0
set pagination off
b main
run
info share
0xb73f26a0 0xb74cd724 Yes /usr/lib/i386-linux-gnu/libcairo.so.2
find /b 0xb73f26a0, 0xb74cd724, 0x51, 0x14, 0x89, 0x54, 0x24, 0x04, 0xe9, 0x1b, 0xe5, 0xfa, 0xff, 0x8d, 0x76, 0x00, 0x31, 0xc0, 0xc3, 0x8d, 0x74, 0x26, 0x00, 0x90, 0x89, 0xd0, 0xc3, 0x8d, 0xb4, 0x26, 0x00, 0x00, 0x00, 0x00, 0x8d, 0xb6, 0x00, 0x00, 0x00, 0x00, 0x8b, 0x44, 0x24, 0x04, 0x8b, 0x40, 0x08, 0xc3, 0x8d, 0xb4, 0x26, 0x00, 0x00, 0x00, 0x00, 0x90, 0x8b, 0x44, 0x24, 0x04, 0x8b, 0x40, 0x0c, 0xc3, 0x8d, 0xb4
0xb745d2ba <_cairo_surface_tag+4294956810>
1 pattern found.
(gdb) disassemble 0xb745d2a0,0xb745d2ba+20
Dump of assembler code from 0xb745d2a0 to 0xb745d2ce:
0xb745d2a0 <_cairo_surface_set_error+0>: mov 0x8(%esp),%edx
0xb745d2a4 <_cairo_surface_set_error+4>: mov 0x4(%esp),%ecx
0xb745d2a8 <_cairo_surface_set_error+8>: cmp $0x66,%edx
0xb745d2ab <_cairo_surface_set_error+11>: je 0xb745d2c8 <_cairo_surface_set_error+40>
0xb745d2ad <_cairo_surface_set_error+13>: lea -0x1(%edx),%eax
0xb745d2b0 <_cairo_surface_set_error+16>: cmp $0x29,%eax
0xb745d2b3 <_cairo_surface_set_error+19>: ja 0xb745d2d0 <_cairo_surface_set_error+48>
0xb745d2b5 <_cairo_surface_tag+-10491>: xor %eax,%eax
0xb745d2b7 <_cairo_surface_tag+-10489>: lock cmpxchg %edx,0x14(%ecx)
0xb745d2bc <_cairo_surface_set_error+28>: mov %edx,0x4(%esp)
0xb745d2c0 <_cairo_surface_set_error+32>: jmp 0xb740b7e0 <_cairo_error>
0xb745d2c5 <_cairo_surface_set_error+37>: lea 0x0(%esi),%esi
0xb745d2c8 <_cairo_surface_set_error+40>: xor %eax,%eax
0xb745d2ca <_cairo_surface_set_error+42>: ret
0xb745d2cb <_cairo_surface_set_error+43>: lea 0x0(%esi,%eiz,1),%esi
End of assembler dump.
(gdb) b *0xb745d2bc
Breakpoint 3 at 0xb745d2bc: file ../../../../src/cairo-surface.c, line 201.
(gdb) info b
Num Type Disp Enb Address What
2 breakpoint keep y 0xb745d2ba in _cairo_atomic_int_cmpxchg_impl at ../../../../src/cairo-atomic-private.h:118
3 breakpoint keep y 0xb745d2bc in _cairo_surface_set_error at ../../../../src/cairo-surface.c:201
https://sources.debian.org/src/cairo/1.16.0-4/src/cairo-surface.c/#L201
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