Re: [PATCHv2 2/2] rerere: avoid buffer overrun
From: Junio C Hamano <hidden>
Date: 2018-09-11 20:45:05
Elijah Newren [off-list ref] writes:
check_one_conflict() compares `i` to `active_nr` in two places to avoid
buffer overruns, but left out an important third location.
The code did used to have a check here comparing i to active_nr, back
before commit fb70a06da2f1 ("rerere: fix an off-by-one non-bug",
2015-06-28), however the code at the time used an 'if' rather than a
'while' meaning back then that this loop could not have read past the
end of the array, making the check unnecessary and it was removed.
Unfortunately, in commit 5eda906b2873 ("rerere: handle conflicts with
multiple stage #1 entries", 2015-07-24), the 'if' was changed to a
'while' and the check comparing i and active_nr was not re-instated,
leading to this problem.
Signed-off-by: Elijah Newren <redacted>
---Thanks. Looks good to me.
quoted hunk
rerere.c | 2 +- t/t4200-rerere.sh | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)diff --git a/rerere.c b/rerere.c index c7787aa07f..783d4dae2a 100644 --- a/rerere.c +++ b/rerere.c@@ -533,7 +533,7 @@ static int check_one_conflict(int i, int *type) } *type = PUNTED; - while (ce_stage(active_cache[i]) == 1) + while (i < active_nr && ce_stage(active_cache[i]) == 1) i++; /* Only handle regular files with both stages #2 and #3 */diff --git a/t/t4200-rerere.sh b/t/t4200-rerere.sh index f9294b7677..313222d0d6 100755 --- a/t/t4200-rerere.sh +++ b/t/t4200-rerere.sh@@ -596,7 +596,7 @@ test_expect_success 'setup simple stage 1 handling' ' ) ' -test_expect_failure 'test simple stage 1 handling' ' +test_expect_success 'test simple stage 1 handling' ' ( cd stage_1_handling &&