From: Usman Akinyemi <redacted>

Replace unsafe uses of atoi() with strtoul_ui() for unsigned integers
and strtol_i() for signed integers across multiple files. This change
improves error handling and prevents potential integer overflow issues.

The following files were updated:
- daemon.c: Update parsing of --timeout, --init-timeout, and
  --max-connections
- imap-send.c: Improve parsing of UIDVALIDITY, UIDNEXT, APPENDUID, and
  tags
- merge-ll.c: Enhance parsing of marker size in ll_merge and
  ll_merge_marker_size

This change allows for better error detection when parsing integer
values from command-line arguments and IMAP responses, making the code
more robust and secure.

This is a #leftoverbit discussed here:
 https://public-inbox.org/git/CAC4O8c-nuOTS=a0sVp1603KaM2bZjs+yNZzdAaa5CGTNGFE7hQ@mail.gmail.com/

Signed-off-by: Usman Akinyemi <redacted>

Cc: gitster@pobox.com
Cc: Patrick Steinhardt <redacted>
Cc: phillip.wood123@gmail.com
Cc: Christian Couder <redacted>
Cc: Eric Sunshine <redacted>
Cc: Taylor Blau <redacted>
---
 daemon.c    | 14 +++++++++-----
 imap-send.c | 13 ++++++++-----
 merge-ll.c  |  6 ++----
 3 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/daemon.c b/daemon.c
index cb946e3c95f..3fdb6e83c40 100644
--- a/daemon.c
+++ b/daemon.c

@@ -1308,17 +1308,21 @@ int cmd_main(int argc, const char **argv)
                        continue;
                }
                if (skip_prefix(arg, "--timeout=", &v)) {
-                       timeout = atoi(v);
+                       if (strtoul_ui(v, 10, &timeout) < 0) {
+                               die("'%s': not a valid integer for --timeout", v);
+                       }
                        continue;
                }
                if (skip_prefix(arg, "--init-timeout=", &v)) {
-                       init_timeout = atoi(v);
+                       if (strtoul_ui(v, 10, &init_timeout) < 0) {
+                               die("'%s': not a valid integer for --init-timeout", v);
+                       }
                        continue;
                }
                if (skip_prefix(arg, "--max-connections=", &v)) {
-                       max_connections = atoi(v);
-                       if (max_connections < 0)
-                               max_connections = 0;            /* unlimited */
+                       if (strtol_i(v, 10, &max_connections) != 0 || max_connections < 0) {
+                               max_connections = 0;  /* unlimited */
+                       }
                        continue;
                }
                if (!strcmp(arg, "--strict-paths")) {

diff --git a/imap-send.c b/imap-send.c
index ec68a066877..33b74dfded7 100644
--- a/imap-send.c
+++ b/imap-send.c

@@ -668,12 +668,12 @@ static int parse_response_code(struct imap_store *ctx, struct imap_cmd_cb *cb,
                return RESP_BAD;
        }
        if (!strcmp("UIDVALIDITY", arg)) {
-               if (!(arg = next_arg(&s)) || !(ctx->uidvalidity = atoi(arg))) {
+               if (!(arg = next_arg(&s)) || strtol_i(arg, 10, &ctx->uidvalidity) != 0) {
                        fprintf(stderr, "IMAP error: malformed UIDVALIDITY status\n");
                        return RESP_BAD;
                }
        } else if (!strcmp("UIDNEXT", arg)) {
-               if (!(arg = next_arg(&s)) || !(imap->uidnext = atoi(arg))) {
+               if (!(arg = next_arg(&s)) || strtol_i(arg, 10, &imap->uidnext) != 0) {
                        fprintf(stderr, "IMAP error: malformed NEXTUID status\n");
                        return RESP_BAD;
                }

@@ -686,8 +686,8 @@ static int parse_response_code(struct imap_store *ctx, struct imap_cmd_cb *cb,
                for (; isspace((unsigned char)*p); p++);
                fprintf(stderr, "*** IMAP ALERT *** %s\n", p);
        } else if (cb && cb->ctx && !strcmp("APPENDUID", arg)) {
-               if (!(arg = next_arg(&s)) || !(ctx->uidvalidity = atoi(arg)) ||
-                   !(arg = next_arg(&s)) || !(*(int *)cb->ctx = atoi(arg))) {
+               if (!(arg = next_arg(&s)) || (strtol_i(arg, 10, &ctx->uidvalidity) != 0) ||
+                       !(arg = next_arg(&s)) || (strtol_i(arg, 10, (int *)cb->ctx) != 0)) {
                        fprintf(stderr, "IMAP error: malformed APPENDUID status\n");
                        return RESP_BAD;
                }

@@ -773,7 +773,10 @@ static int get_cmd_result(struct imap_store *ctx, struct imap_cmd *tcmd)
                        if (!tcmd)
                                return DRV_OK;
                } else {
-                       tag = atoi(arg);
+                       if (strtol_i(arg, 10, &tag) != 0) {
+                               fprintf(stderr, "IMAP error: malformed tag %s\n", arg);
+                               return RESP_BAD;
+                       }
                        for (pcmdp = &imap->in_progress; (cmdp = *pcmdp); pcmdp = &cmdp->next)
                                if (cmdp->tag == tag)
                                        goto gottag;

diff --git a/merge-ll.c b/merge-ll.c
index 8e63071922b..2bfee0f2c6b 100644
--- a/merge-ll.c
+++ b/merge-ll.c

@@ -427,8 +427,7 @@ enum ll_merge_result ll_merge(mmbuffer_t *result_buf,
        git_check_attr(istate, path, check);
        ll_driver_name = check->items[0].value;
        if (check->items[1].value) {
-               marker_size = atoi(check->items[1].value);
-               if (marker_size <= 0)
+               if (strtol_i(check->items[1].value, 10, &marker_size) != 0 || marker_size <= 0)
                        marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
        }
        driver = find_ll_merge_driver(ll_driver_name);

@@ -454,8 +453,7 @@ int ll_merge_marker_size(struct index_state *istate, const char *path)
                check = attr_check_initl("conflict-marker-size", NULL);
        git_check_attr(istate, path, check);
        if (check->items[0].value) {
-               marker_size = atoi(check->items[0].value);
-               if (marker_size <= 0)
+               if (strtol_i(check->items[0].value, 10, &marker_size) != 0 || marker_size <= 0)
                        marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
        }
        return marker_size;
--

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