It's the infinite loop of trapped SIGTERMs that raises this exception, and can be performed in any way that deliberately infinitely loops a signal trap.
$ bash -c 'trap "kill 0" EXIT SIGTERM' Segmentation fault (core dumped) $ bash -c 'trap "kill $$" EXIT SIGTERM' Segmentation fault (core dumped) $ bash -c 'trap "kill 0" SIGTERM; kill 0' Segmentation fault (core dumped) $ bash -c 'trap "kill -USR1 $$" SIGUSR1; while :; do :; done' & [1] 18769 $ kill -USR1 18769 [1]+ Segmentation fault (core dumped) bash -c 'trap "kill -USR1 $$" SIGUSR1; while :; do :; done' bash_4.3-6ubuntu1 is the first version that exhibits this behaviour; versions <= bash_4.2-5ubuntu3 are not susceptible. $ bash_4.2-5ubuntu3_amd64/bin/bash -c 'trap "echo trap; kill 0" EXIT SIGTERM' trap trap trap $ bash_4.2-5ubuntu3_amd64/bin/bash -c 'trap "echo trap; kill 0" SIGTERM; kill 0' trap trap $ bash_4.3-6ubuntu1_amd64/bin/bash -c 'trap "echo trap; kill 0" EXIT SIGTERM' trap trap trap trap [...] trap trap Segmentation fault (core dumped) -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to bash in Ubuntu. https://bugs.launchpad.net/bugs/1337827 Title: Bash crashes with a segmentation fault on "trap 'kill 0' SIGTERM EXIT" Status in “bash” package in Ubuntu: Confirmed Bug description: Trusty's bash (4.3-7ubuntu1) crashes with a segmentation fault on the following trap statement: trap 'kill 0' SIGTERM EXIT Apport doesn't react to this crash and so I wasn't able to submit this bug via Apport. :-/ $ dpkg-query --show --showformat '${Package}\t${Version}\t${Architecture}\n' bash bash 4.3-7ubuntu1 amd64 $ cat test.sh #!/bin/bash trap 'kill 0' SIGTERM EXIT $ ./test.sh ; echo $? Segmentation fault (core dumped) 139 $ gdb --args /bin/bash test.sh (with nostrip and noopt bash build) (gdb) bt #0 0x00007ffff761e267 in kill () at ../sysdeps/unix/syscall-template.S:81 #1 0x000000000044fbf2 in kill_pid (pid=0, sig=15, group=0) at .././jobs.c:3158 #2 0x0000000000494a09 in kill_builtin (list=0x7388a8) at ../.././builtins/../.././builtins/kill.def:186 #3 0x000000000043c7c0 in execute_builtin (builtin=0x494601 <kill_builtin>, words=0x738908, flags=0, subshell=0) at .././execute_cmd.c:4337 #4 0x000000000043d3d0 in execute_builtin_or_function (words=0x738908, builtin=0x494601 <kill_builtin>, var=0x0, redirects=0x0, fds_to_close=0x738808, flags=0) at .././execute_cmd.c:4758 #5 0x000000000043c271 in execute_simple_command (simple_command=0x73a0c8, pipe_in=-1, pipe_out=-1, async=0, fds_to_close=0x738808) at .././execute_cmd.c:4161 #6 0x0000000000435fe1 in execute_command_internal (command=0x73a088, asynchronous=0, pipe_in=-1, pipe_out=-1, fds_to_close=0x738808) at .././execute_cmd.c:787 #7 0x0000000000490123 in parse_and_execute (string=0x737588 "kill 0", from_file=0x4e275f "exit trap", flags=21) at ../.././builtins/evalstring.c:367 #8 0x00000000004697ef in run_exit_trap () at .././trap.c:846 #9 0x000000000041ef9e in exit_shell (s=0) at .././shell.c:915 #10 0x000000000041eacf in main (argc=2, argv=0x7fffffffdef8, env=0x7fffffffdf10) at .././shell.c:756 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/bash/+bug/1337827/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
