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* [PATCH v2] pager: fix crash when pager program doesn't exist
@ 2021-11-20 19:40 Enzo Matsumiya
  2021-11-21 18:37 ` Jeff King
  0 siblings, 1 reply; 71+ messages in thread
From: Enzo Matsumiya @ 2021-11-20 19:40 UTC (permalink / raw)
  To: git; +Cc: Enzo Matsumiya, Jeff King

When prepare_cmd() fails for, e.g., pager process setup,
child_process_clear() frees the memory in pager_process.args, but .argv
still points to the previously location.

When setup_pager() is called a second time, from cmd_log_init_finish()
in this case, its strvec operations (i.e. using pager_process.argv) will
lead to a use-after-free.

This patch makes sure that further uses of the child_process cleared by
child_process_clear() gets a properly initialized struct.

Reproducer:
$ git config pager.show INVALID_PAGER
$ git show $VALID_COMMIT
error: cannot run INVALID_PAGER: No such file or directory
[1]    3619 segmentation fault (core dumped)  git show $VALID_COMMIT

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Reviewed-by: Jeff King <peff@peff.net>
---
Changes to v1:
 * Implement all of Jeff's suggestions:
   - remove double frees to .argv
   - discard the idea of falling back to DEFAULT_PAGER
   - replace memset() in child_process_clear() by child_process_init()
   - update/improve commit message

 run-command.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/run-command.c b/run-command.c
index f329391154ae..a7bf81025afb 100644
--- a/run-command.c
+++ b/run-command.c
@@ -19,6 +19,7 @@ void child_process_clear(struct child_process *child)
 {
 	strvec_clear(&child->args);
 	strvec_clear(&child->env_array);
+	child_process_init(child);
 }
 
 struct child_to_clean {
-- 
2.33.1


^ permalink raw reply related	[flat|nested] 71+ messages in thread

end of thread, other threads:[~2021-11-26  9:50 UTC | newest]

Thread overview: 71+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-11-20 19:40 [PATCH v2] pager: fix crash when pager program doesn't exist Enzo Matsumiya
2021-11-21 18:37 ` Jeff King
2021-11-22  2:10   ` Junio C Hamano
2021-11-22  4:35     ` Jeff King
2021-11-22 14:52       ` Enzo Matsumiya
2021-11-22 17:05         ` Junio C Hamano
2021-11-23 16:40           ` Enzo Matsumiya
2021-11-24  1:55             ` Ævar Arnfjörð Bjarmason
2021-11-24 15:51               ` Jeff King
2021-11-22 16:04       ` [PATCH 0/5] run-command API: get rid of "argv" Ævar Arnfjörð Bjarmason
2021-11-22 16:04         ` [PATCH 1/5] archive-tar: use our own cmd.buf in error message Ævar Arnfjörð Bjarmason
2021-11-22 21:04           ` Junio C Hamano
2021-11-22 16:04         ` [PATCH 2/5] upload-archive: use regular "struct child_process" pattern Ævar Arnfjörð Bjarmason
2021-11-22 17:02           ` Jeff King
2021-11-22 20:53           ` Ævar Arnfjörð Bjarmason
2021-11-22 21:10             ` Jeff King
2021-11-22 21:36               ` Ævar Arnfjörð Bjarmason
2021-11-22 16:04         ` [PATCH 3/5] run-command API users: use strvec_pushv(), not argv assignment Ævar Arnfjörð Bjarmason
2021-11-22 21:19           ` Junio C Hamano
2021-11-22 21:30             ` Ævar Arnfjörð Bjarmason
2021-11-22 16:04         ` [PATCH 4/5] run-command API users: use strvec_pushl(), not argv construction Ævar Arnfjörð Bjarmason
2021-11-22 16:04         ` [PATCH 5/5] run-command API: remove "argv" member, always use "args" Ævar Arnfjörð Bjarmason
2021-11-22 17:32           ` Jeff King
2021-11-22 18:19             ` Ævar Arnfjörð Bjarmason
2021-11-22 18:47               ` Jeff King
2021-11-22 17:52         ` [PATCH 0/5] run-command API: get rid of "argv" Jeff King
2021-11-22 18:11           ` Junio C Hamano
2021-11-22 18:33             ` Ævar Arnfjörð Bjarmason
2021-11-22 18:49               ` Jeff King
2021-11-22 18:26           ` Ævar Arnfjörð Bjarmason
2021-11-23 12:06         ` [PATCH v2 0/9] run-command API: get rid of "argv" and "env" Ævar Arnfjörð Bjarmason
2021-11-23 12:06           ` [PATCH v2 1/9] worktree: remove redundant NULL-ing of "cp.argv Ævar Arnfjörð Bjarmason
2021-11-23 15:26             ` Eric Sunshine
2021-11-24  1:54               ` Junio C Hamano
2021-11-24  6:00                 ` Eric Sunshine
2021-11-24  6:12                   ` Eric Sunshine
2021-11-24  5:44               ` Eric Sunshine
2021-11-23 12:06           ` [PATCH v2 2/9] upload-archive: use regular "struct child_process" pattern Ævar Arnfjörð Bjarmason
2021-11-23 12:06           ` [PATCH v2 3/9] run-command API users: use strvec_pushv(), not argv assignment Ævar Arnfjörð Bjarmason
2021-11-23 12:06           ` [PATCH v2 4/9] run-command tests: " Ævar Arnfjörð Bjarmason
2021-11-24  1:33             ` Eric Sunshine
2021-11-23 12:06           ` [PATCH v2 5/9] run-command API users: use strvec_pushl(), not argv construction Ævar Arnfjörð Bjarmason
2021-11-23 12:06           ` [PATCH v2 6/9] run-command API users: use strvec_push(), " Ævar Arnfjörð Bjarmason
2021-11-23 12:06           ` [PATCH v2 7/9] run-command API: remove "argv" member, always use "args" Ævar Arnfjörð Bjarmason
2021-11-23 12:06           ` [PATCH v2 8/9] difftool: use "env_array" to simplify memory management Ævar Arnfjörð Bjarmason
2021-11-23 12:06           ` [PATCH v2 9/9] run-command API: remove "env" member, always use "env_array" Ævar Arnfjörð Bjarmason
2021-11-25 22:52           ` [PATCH v3 0/9] run-command API: get rid of "argv" and "env" Ævar Arnfjörð Bjarmason
2021-11-25 22:52             ` [PATCH v3 1/9] worktree: stop being overly intimate with run_command() internals Ævar Arnfjörð Bjarmason
2021-11-26  9:48               ` Eric Sunshine
2021-11-25 22:52             ` [PATCH v3 2/9] upload-archive: use regular "struct child_process" pattern Ævar Arnfjörð Bjarmason
2021-11-25 22:52             ` [PATCH v3 3/9] run-command API users: use strvec_pushv(), not argv assignment Ævar Arnfjörð Bjarmason
2021-11-25 22:52             ` [PATCH v3 4/9] run-command tests: " Ævar Arnfjörð Bjarmason
2021-11-25 22:52             ` [PATCH v3 5/9] run-command API users: use strvec_pushl(), not argv construction Ævar Arnfjörð Bjarmason
2021-11-25 22:52             ` [PATCH v3 6/9] run-command API users: use strvec_push(), " Ævar Arnfjörð Bjarmason
2021-11-25 22:52             ` [PATCH v3 7/9] run-command API: remove "argv" member, always use "args" Ævar Arnfjörð Bjarmason
2021-11-25 22:52             ` [PATCH v3 8/9] difftool: use "env_array" to simplify memory management Ævar Arnfjörð Bjarmason
2021-11-25 22:52             ` [PATCH v3 9/9] run-command API: remove "env" member, always use "env_array" Ævar Arnfjörð Bjarmason
2021-11-22 15:31     ` [PATCH v2] pager: fix crash when pager program doesn't exist Enzo Matsumiya
2021-11-22 16:22       ` Ævar Arnfjörð Bjarmason
2021-11-22 16:46         ` Enzo Matsumiya
2021-11-22 17:10           ` Ævar Arnfjörð Bjarmason
2021-11-22 17:41             ` Jeff King
2021-11-22 18:00             ` Junio C Hamano
2021-11-22 18:26               ` Jeff King
2021-11-22 17:55           ` Junio C Hamano
2021-11-22 18:19             ` Junio C Hamano
2021-11-22 18:37               ` Jeff King
2021-11-22 20:39                 ` Junio C Hamano
2021-11-22 17:08         ` Junio C Hamano
2021-11-22 18:35           ` Ævar Arnfjörð Bjarmason
2021-11-22 16:30       ` Jeff King

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