From: Andrzej Hunt <ajrhunt@xxxxxxxxxx>
setup_unpack_trees_porcelain() populates various fields on
unpack_tree_opts, we need to call clear_unpack_trees_porcelain() to
avoid leaking them. Specifically, we used to leak
unpack_tree_opts.msgs_to_free.
We have to do this in leave_reset_head because there are multiple
scenarios where unpack_tree_opts has already been configured, followed
by a 'goto leave_reset_head'. But we can also 'goto leave_reset_head'
prior to having initialised unpack_tree_opts via memset(..., 0, ...).
Therefore we also move unpack_tree_opts initialisation to the start of
reset_head(), and convert it to use brace initialisation - which
guarantees that we can never clear an unitialised unpack_tree_opts.
clear_unpack_tree_opts() is always safe to call as long as
unpack_tree_opts is at least zero-initialised, i.e. it does not depend
on a previous call to setup_unpack_trees_porcelain().
LSAN output from t0021:
Direct leak of 192 byte(s) in 1 object(s) allocated from:
#0 0x49ab49 in realloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
#1 0xa721e5 in xrealloc wrapper.c:126:8
#2 0x9f7861 in strvec_push_nodup strvec.c:19:2
#3 0x9f7861 in strvec_pushf strvec.c:39:2
#4 0xa43e14 in setup_unpack_trees_porcelain unpack-trees.c:129:3
#5 0x97e011 in reset_head reset.c:53:2
#6 0x61dfa5 in cmd_rebase builtin/rebase.c:1991:9
#7 0x4ce83e in run_builtin git.c:475:11
#8 0x4ccafe in handle_builtin git.c:729:3
#9 0x4cb01c in run_argv git.c:818:4
#10 0x4cb01c in cmd_main git.c:949:19
#11 0x6b3f3d in main common-main.c:52:11
#12 0x7fa8addf3349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Indirect leak of 147 byte(s) in 1 object(s) allocated from:
#0 0x49ab49 in realloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
#1 0xa721e5 in xrealloc wrapper.c:126:8
#2 0x9e8d54 in strbuf_grow strbuf.c:98:2
#3 0x9e8d54 in strbuf_vaddf strbuf.c:401:3
#4 0x9f7774 in strvec_pushf strvec.c:36:2
#5 0xa43e14 in setup_unpack_trees_porcelain unpack-trees.c:129:3
#6 0x97e011 in reset_head reset.c:53:2
#7 0x61dfa5 in cmd_rebase builtin/rebase.c:1991:9
#8 0x4ce83e in run_builtin git.c:475:11
#9 0x4ccafe in handle_builtin git.c:729:3
#10 0x4cb01c in run_argv git.c:818:4
#11 0x4cb01c in cmd_main git.c:949:19
#12 0x6b3f3d in main common-main.c:52:11
#13 0x7fa8addf3349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Indirect leak of 134 byte(s) in 1 object(s) allocated from:
#0 0x49ab49 in realloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
#1 0xa721e5 in xrealloc wrapper.c:126:8
#2 0x9e8d54 in strbuf_grow strbuf.c:98:2
#3 0x9e8d54 in strbuf_vaddf strbuf.c:401:3
#4 0x9f7774 in strvec_pushf strvec.c:36:2
#5 0xa43fe4 in setup_unpack_trees_porcelain unpack-trees.c:168:3
#6 0x97e011 in reset_head reset.c:53:2
#7 0x61dfa5 in cmd_rebase builtin/rebase.c:1991:9
#8 0x4ce83e in run_builtin git.c:475:11
#9 0x4ccafe in handle_builtin git.c:729:3
#10 0x4cb01c in run_argv git.c:818:4
#11 0x4cb01c in cmd_main git.c:949:19
#12 0x6b3f3d in main common-main.c:52:11
#13 0x7fa8addf3349 in __libc_start_main (/lib64/libc.so.6+0x24349)
Indirect leak of 130 byte(s) in 1 object(s) allocated from:
#0 0x49ab49 in realloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3
#1 0xa721e5 in xrealloc wrapper.c:126:8
#2 0x9e8d54 in strbuf_grow strbuf.c:98:2
#3 0x9e8d54 in strbuf_vaddf strbuf.c:401:3
#4 0x9f7774 in strvec_pushf strvec.c:36:2
#5 0xa43f20 in setup_unpack_trees_porcelain unpack-trees.c:150:3
#6 0x97e011 in reset_head reset.c:53:2
#7 0x61dfa5 in cmd_rebase builtin/rebase.c:1991:9
#8 0x4ce83e in run_builtin git.c:475:11
#9 0x4ccafe in handle_builtin git.c:729:3
#10 0x4cb01c in run_argv git.c:818:4
#11 0x4cb01c in cmd_main git.c:949:19
#12 0x6b3f3d in main common-main.c:52:11
#13 0x7fa8addf3349 in __libc_start_main (/lib64/libc.so.6+0x24349)
SUMMARY: AddressSanitizer: 603 byte(s) leaked in 4 allocation(s).
Signed-off-by: Andrzej Hunt <andrzej@xxxxxxxxx>
---
reset.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/reset.c b/reset.c
index 4bea758053..79310ae071 100644
--- a/reset.c
+++ b/reset.c
@@ -21,7 +21,7 @@ int reset_head(struct repository *r, struct object_id *oid, const char *action,
struct object_id head_oid;
struct tree_desc desc[2] = { { NULL }, { NULL } };
struct lock_file lock = LOCK_INIT;
- struct unpack_trees_options unpack_tree_opts;
+ struct unpack_trees_options unpack_tree_opts = { 0 };
struct tree *tree;
const char *reflog_action;
struct strbuf msg = STRBUF_INIT;
@@ -49,7 +49,6 @@ int reset_head(struct repository *r, struct object_id *oid, const char *action,
if (refs_only)
goto reset_head_refs;
- memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
setup_unpack_trees_porcelain(&unpack_tree_opts, action);
unpack_tree_opts.head_idx = 1;
unpack_tree_opts.src_index = r->index;
@@ -134,6 +133,7 @@ int reset_head(struct repository *r, struct object_id *oid, const char *action,
leave_reset_head:
strbuf_release(&msg);
rollback_lock_file(&lock);
+ clear_unpack_trees_porcelain(&unpack_tree_opts);
while (nr)
free((void *)desc[--nr].buffer);
return ret;
--
2.26.2
