diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
index 6e5d1e4..20605f2 100644
--- a/qemu-io-cmds.c
+++ b/qemu-io-cmds.c
@@ -294,9 +294,10 @@ static void qemu_io_free(void *p)
     qemu_vfree(p);
 }
 
-static void dump_buffer(const void *buffer, int64_t offset, int len)
+static void dump_buffer(const void *buffer, int64_t offset, int64_t len)
 {
-    int i, j;
+    uint64_t i;
+    int j;
     const uint8_t *p;
 
     for (i = 0, p = buffer; i < len; i += 16) {
@@ -319,7 +320,7 @@ static void dump_buffer(const void *buffer, int64_t offset, int len)
 }
 
 static void print_report(const char *op, struct timeval *t, int64_t offset,
-                         int count, int total, int cnt, int Cflag)
+                         int64_t count, int64_t total, int cnt, int Cflag)
 {
     char s1[64], s2[64], ts[64];
 
@@ -327,12 +328,12 @@ static void print_report(const char *op, struct timeval *t, int64_t offset,
     if (!Cflag) {
         cvtstr((double)total, s1, sizeof(s1));
         cvtstr(tdiv((double)total, *t), s2, sizeof(s2));
-        printf("%s %d/%d bytes at offset %" PRId64 "\n",
+        printf("%s %"PRId64"/%"PRId64" bytes at offset %" PRId64 "\n",
                op, total, count, offset);
         printf("%s, %d ops; %s (%s/sec and %.4f ops/sec)\n",
                s1, cnt, ts, s2, tdiv((double)cnt, *t));
     } else {/* bytes,ops,time,bytes/sec,ops/sec */
-        printf("%d,%d,%s,%.3f,%.3f\n",
+        printf("%"PRId64",%d,%s,%.3f,%.3f\n",
             total, cnt, ts,
             tdiv((double)total, *t),
             tdiv((double)cnt, *t));
@@ -393,11 +394,15 @@ fail:
     return buf;
 }
 
-static int do_read(BlockBackend *blk, char *buf, int64_t offset, int count,
-                   int *total)
+static int do_read(BlockBackend *blk, char *buf, int64_t offset, int64_t count,
+                   int64_t *total)
 {
     int ret;
 
+    if (count >> 9 > INT_MAX) {
+        return -ERANGE;
+    }
+
     ret = blk_read(blk, offset >> 9, (uint8_t *)buf, count >> 9);
     if (ret < 0) {
         return ret;
@@ -406,11 +411,15 @@ static int do_read(BlockBackend *blk, char *buf, int64_t offset, int count,
     return 1;
 }
 
-static int do_write(BlockBackend *blk, char *buf, int64_t offset, int count,
-                    int *total)
+static int do_write(BlockBackend *blk, char *buf, int64_t offset, int64_t count,
+                    int64_t *total)
 {
     int ret;
 
+    if (count >> 9 > INT_MAX) {
+        return -ERANGE;
+    }
+
     ret = blk_write(blk, offset >> 9, (uint8_t *)buf, count >> 9);
     if (ret < 0) {
         return ret;
@@ -419,9 +428,13 @@ static int do_write(BlockBackend *blk, char *buf, int64_t offset, int count,
     return 1;
 }
 
-static int do_pread(BlockBackend *blk, char *buf, int64_t offset, int count,
-                    int *total)
+static int do_pread(BlockBackend *blk, char *buf, int64_t offset,
+                    int64_t count, int64_t *total)
 {
+    if (count > INT_MAX) {
+        return -ERANGE;
+    }
+
     *total = blk_pread(blk, offset, (uint8_t *)buf, count);
     if (*total < 0) {
         return *total;
@@ -429,9 +442,13 @@ static int do_pread(BlockBackend *blk, char *buf, int64_t offset, int count,
     return 1;
 }
 
-static int do_pwrite(BlockBackend *blk, char *buf, int64_t offset, int count,
-                     int *total)
+static int do_pwrite(BlockBackend *blk, char *buf, int64_t offset,
+                     int64_t count, int64_t *total)
 {
+    if (count > INT_MAX) {
+        return -ERANGE;
+    }
+
     *total = blk_pwrite(blk, offset, (uint8_t *)buf, count);
     if (*total < 0) {
         return *total;
@@ -442,8 +459,8 @@ static int do_pwrite(BlockBackend *blk, char *buf, int64_t offset, int count,
 typedef struct {
     BlockBackend *blk;
     int64_t offset;
-    int count;
-    int *total;
+    int64_t count;
+    int64_t *total;
     int ret;
     bool done;
 } CoWriteZeroes;
@@ -463,8 +480,8 @@ static void coroutine_fn co_write_zeroes_entry(void *opaque)
     *data->total = data->count;
 }
 
-static int do_co_write_zeroes(BlockBackend *blk, int64_t offset, int count,
-                              int *total)
+static int do_co_write_zeroes(BlockBackend *blk, int64_t offset, int64_t count,
+                              int64_t *total)
 {
     Coroutine *co;
     CoWriteZeroes data = {
@@ -475,6 +492,10 @@ static int do_co_write_zeroes(BlockBackend *blk, int64_t offset, int count,
         .done   = false,
     };
 
+    if (count >> BDRV_SECTOR_BITS > INT_MAX) {
+        return -ERANGE;
+    }
+
     co = qemu_coroutine_create(co_write_zeroes_entry);
     qemu_coroutine_enter(co, &data);
     while (!data.done) {
@@ -488,10 +509,14 @@ static int do_co_write_zeroes(BlockBackend *blk, int64_t offset, int count,
 }
 
 static int do_write_compressed(BlockBackend *blk, char *buf, int64_t offset,
-                               int count, int *total)
+                               int64_t count, int64_t *total)
 {
     int ret;
 
+    if (count >> 9 > INT_MAX) {
+        return -ERANGE;
+    }
+
     ret = blk_write_compressed(blk, offset >> 9, (uint8_t *)buf, count >> 9);
     if (ret < 0) {
         return ret;
@@ -501,8 +526,12 @@ static int do_write_compressed(BlockBackend *blk, char *buf, int64_t offset,
 }
 
 static int do_load_vmstate(BlockBackend *blk, char *buf, int64_t offset,
-                           int count, int *total)
+                           int64_t count, int64_t *total)
 {
+    if (count > INT_MAX) {
+        return -ERANGE;
+    }
+
     *total = blk_load_vmstate(blk, (uint8_t *)buf, offset, count);
     if (*total < 0) {
         return *total;
@@ -511,8 +540,12 @@ static int do_load_vmstate(BlockBackend *blk, char *buf, int64_t offset,
 }
 
 static int do_save_vmstate(BlockBackend *blk, char *buf, int64_t offset,
-                           int count, int *total)
+                           int64_t count, int64_t *total)
 {
+    if (count > INT_MAX) {
+        return -ERANGE;
+    }
+
     *total = blk_save_vmstate(blk, (uint8_t *)buf, offset, count);
     if (*total < 0) {
         return *total;
@@ -642,10 +675,11 @@ static int read_f(BlockBackend *blk, int argc, char **argv)
     int c, cnt;
     char *buf;
     int64_t offset;
-    int count;
+    int64_t count;
     /* Some compilers get confused and warn if this is not initialized.  */
-    int total = 0;
-    int pattern = 0, pattern_offset = 0, pattern_count = 0;
+    int64_t total = 0;
+    int pattern = 0;
+    int64_t pattern_offset = 0, pattern_count = 0;
 
     while ((c = getopt(argc, argv, "bCl:pP:qs:v")) != -1) {
         switch (c) {
@@ -712,6 +746,9 @@ static int read_f(BlockBackend *blk, int argc, char **argv)
     if (count < 0) {
         printf("non-numeric length argument -- %s\n", argv[optind]);
         return 0;
+    } else if (count > SIZE_MAX) {
+        printf("length cannot exceed %zu, given %s\n", SIZE_MAX, argv[optind]);
+        return 0;
     }
 
     if (!Pflag && (lflag || sflag)) {
@@ -734,7 +771,7 @@ static int read_f(BlockBackend *blk, int argc, char **argv)
             return 0;
         }
         if (count & 0x1ff) {
-            printf("count %d is not sector aligned\n",
+            printf("count %"PRId64" is not sector aligned\n",
                    count);
             return 0;
         }
@@ -762,7 +799,7 @@ static int read_f(BlockBackend *blk, int argc, char **argv)
         memset(cmp_buf, pattern, pattern_count);
         if (memcmp(buf + pattern_offset, cmp_buf, pattern_count)) {
             printf("Pattern verification failed at offset %"
-                   PRId64 ", %d bytes\n",
+                   PRId64 ", %"PRId64" bytes\n",
                    offset + pattern_offset, pattern_count);
         }
         g_free(cmp_buf);
@@ -957,9 +994,9 @@ static int write_f(BlockBackend *blk, int argc, char **argv)
     int c, cnt;
     char *buf = NULL;
     int64_t offset;
-    int count;
+    int64_t count;
     /* Some compilers get confused and warn if this is not initialized.  */
-    int total = 0;
+    int64_t total = 0;
     int pattern = 0xcd;
 
     while ((c = getopt(argc, argv, "bcCpP:qz")) != -1) {
@@ -1019,6 +1056,9 @@ static int write_f(BlockBackend *blk, int argc, char **argv)
     if (count < 0) {
         printf("non-numeric length argument -- %s\n", argv[optind]);
         return 0;
+    } else if (count > SIZE_MAX) {
+        printf("length cannot exceed %zu, given %s\n", SIZE_MAX, argv[optind]);
+        return 0;
     }
 
     if (!pflag) {
@@ -1029,7 +1069,7 @@ static int write_f(BlockBackend *blk, int argc, char **argv)
         }
 
         if (count & 0x1ff) {
-            printf("count %d is not sector aligned\n",
+            printf("count %"PRId64" is not sector aligned\n",
                    count);
             return 0;
         }
@@ -1777,8 +1817,7 @@ static int discard_f(BlockBackend *blk, int argc, char **argv)
     struct timeval t1, t2;
     int Cflag = 0, qflag = 0;
     int c, ret;
-    int64_t offset;
-    int count;
+    int64_t offset, count;
 
     while ((c = getopt(argc, argv, "Cq")) != -1) {
         switch (c) {
@@ -1808,6 +1847,11 @@ static int discard_f(BlockBackend *blk, int argc, char **argv)
     if (count < 0) {
         printf("non-numeric length argument -- %s\n", argv[optind]);
         return 0;
+    } else if (count >> BDRV_SECTOR_BITS > INT_MAX) {
+        printf("length cannot exceed %"PRIu64", given %s\n",
+               (uint64_t)INT_MAX << BDRV_SECTOR_BITS,
+               argv[optind]);
+        return 0;
     }
 
     gettimeofday(&t1, NULL);
@@ -1833,11 +1877,10 @@ out:
 static int alloc_f(BlockBackend *blk, int argc, char **argv)
 {
     BlockDriverState *bs = blk_bs(blk);
-    int64_t offset, sector_num;
-    int nb_sectors, remaining;
+    int64_t offset, sector_num, nb_sectors, remaining;
     char s1[64];
-    int num, sum_alloc;
-    int ret;
+    int num, ret;
+    int64_t sum_alloc;
 
     offset = cvtnum(argv[1]);
     if (offset < 0) {
@@ -1854,6 +1897,10 @@ static int alloc_f(BlockBackend *blk, int argc, char **argv)
         if (nb_sectors < 0) {
             printf("non-numeric length argument -- %s\n", argv[2]);
             return 0;
+        } else if (nb_sectors > INT_MAX) {
+            printf("length argument cannot exceed %d, given %s\n",
+                   INT_MAX, argv[2]);
+            return 0;
         }
     } else {
         nb_sectors = 1;
@@ -1881,7 +1928,7 @@ static int alloc_f(BlockBackend *blk, int argc, char **argv)
 
     cvtstr(offset, s1, sizeof(s1));
 
-    printf("%d/%d sectors allocated at offset %s\n",
+    printf("%"PRId64"/%"PRId64" sectors allocated at offset %s\n",
            sum_alloc, nb_sectors, s1);
     return 0;
 }
@@ -2191,10 +2238,14 @@ static const cmdinfo_t sigraise_cmd = {
 
 static int sigraise_f(BlockBackend *blk, int argc, char **argv)
 {
-    int sig = cvtnum(argv[1]);
+    int64_t sig = cvtnum(argv[1]);
     if (sig < 0) {
         printf("non-numeric signal number argument -- %s\n", argv[1]);
         return 0;
+    } else if (sig > NSIG) {
+        printf("signal argument '%s' is too large to be a valid signal\n",
+               argv[1]);
+        return 0;
     }
 
     /* Using raise() to kill this process does not necessarily flush all open
