Merge pull request #29601 from yuwata/mmap-check-overflow

mmap: check offset and size more carefully

src/shared/elf-util.c

@@ -588,7 +588,7 @@ static int parse_core(int fd, const char *executable, char **ret, JsonVariant **
 
         assert(fd >= 0);
 
-        if (lseek(fd, 0, SEEK_SET) == (off_t) -1)
+        if (lseek(fd, 0, SEEK_SET) < 0)
                 return log_warning_errno(errno, "Failed to seek to beginning of the core file: %m");
 
         if (ret && !memstream_init(&c.m))
@@ -644,7 +644,7 @@ static int parse_elf(int fd, const char *executable, char **ret, JsonVariant **r
 
         assert(fd >= 0);
 
-        if (lseek(fd, 0, SEEK_SET) == (off_t) -1)
+        if (lseek(fd, 0, SEEK_SET) < 0)
                 return log_warning_errno(errno, "Failed to seek to beginning of the ELF file: %m");
 
         if (ret && !memstream_init(&c.m))

src/shared/machine-id-setup.c

@@ -151,7 +151,7 @@ int machine_id_setup(const char *root, bool force_transient, sd_id128_t machine_
         }
 
         if (writable) {
-                if (lseek(fd, 0, SEEK_SET) == (off_t) -1)
+                if (lseek(fd, 0, SEEK_SET) < 0)
                         return log_error_errno(errno, "Failed to seek %s: %m", etc_machine_id);
 
                 if (ftruncate(fd, 0) < 0)

src/shared/tpm2-util.c

@@ -4594,7 +4594,7 @@ static int tpm2_userspace_log(
         if (r < 0)
                 return log_debug_errno(r, "Failed to format JSON: %m");
 
-        if (lseek(fd, 0, SEEK_END) == (off_t) -1)
+        if (lseek(fd, 0, SEEK_END) < 0)
                 return log_debug_errno(errno, "Failed to seek to end of JSON log: %m");
 
         r = loop_write(fd, f, SIZE_MAX);