From de2f990a98718d15bff074b9ae65f2eb92a2f938 Mon Sep 17 00:00:00 2001 From: Samuel Mendoza-Jonas Date: Wed, 7 Sep 2016 15:36:40 +1000 Subject: lib/file: Fix errors found by Coverity scan Fix several errors in copy_file_secure_dest() found by Coverity and some minor formatting issues: 143603: Correctly handle mkstemp() return value 143605: Avoid accessing dest_filename[-1] on readlink() error 143606, 143610: Avoid accessing dest_filename[sizeof(dest_filename)] 143607: Fix incorrectly passing sizeof(pointer) to fread() 143608, 143611: Cleanup resources on early exit 143609: Explicitly set umask before calling mkstemp() Signed-off-by: Samuel Mendoza-Jonas --- lib/file/file.c | 85 ++++++++++++++++++++++++++++++++++----------------------- 1 file changed, 51 insertions(+), 34 deletions(-) diff --git a/lib/file/file.c b/lib/file/file.c index 6a270a3..0d18788 100644 --- a/lib/file/file.c +++ b/lib/file/file.c @@ -33,32 +33,52 @@ static const int max_file_size = 1024 * 1024; -int copy_file_secure_dest(void *ctx, - const char *source_file, char **destination_file) { - int result = 0; - char template[] = "/tmp/petitbootXXXXXX"; +int copy_file_secure_dest(void *ctx, const char *source_file, + char **destination_file) +{ + char readlink_buffer[MAX_FILENAME_SIZE + 1]; char dest_filename[MAX_FILENAME_SIZE] = ""; - FILE *source_handle = fopen(source_file, "r"); - int destination_fd = mkstemp(template); - FILE *destination_handle = fdopen(destination_fd, "w"); - if (!source_handle || !(destination_handle)) { - // handle open error - pb_log("%s: failed: unable to open source file '%s'\n", + char template[] = "/tmp/petitbootXXXXXX"; + FILE *destination_handle, *source_handle; + int destination_fd, result = 0; + unsigned char *buffer; + ssize_t r; + size_t l1; + mode_t oldmask; + + source_handle = fopen(source_file, "r"); + if (!source_handle) { + pb_log("%s: unable to open source file '%s': %m\n", __func__, source_file); + return -1; + } + + oldmask = umask(0644); + destination_fd = mkstemp(template); + umask(oldmask); + if (destination_fd < 0) { + pb_log("%s: unable to create temp file, %m\n", __func__); + fclose(source_handle); + return -1; + } + destination_handle = fdopen(destination_fd, "w"); + if (!destination_handle) { + pb_log("%s: unable to open destination file, %m\n", __func__); + fclose(source_handle); + close(destination_fd); return -1; } - size_t l1; - unsigned char *buffer; buffer = talloc_array(ctx, unsigned char, FILE_XFER_BUFFER_SIZE); if (!buffer) { pb_log("%s: failed: unable to allocate file transfer buffer\n", __func__); - return -1; + result = -1; + goto out; } /* Copy data */ - while ((l1 = fread(buffer, 1, sizeof buffer, source_handle)) > 0) { + while ((l1 = fread(buffer, 1, FILE_XFER_BUFFER_SIZE, source_handle)) > 0) { size_t l2 = fwrite(buffer, 1, l1, destination_handle); if (l2 < l1) { if (ferror(destination_handle)) { @@ -76,32 +96,29 @@ int copy_file_secure_dest(void *ctx, } } - talloc_free(buffer); - if (result) { - dest_filename[0] = '\0'; + *destination_file = NULL; + goto out; } - else { - ssize_t r; - char readlink_buffer[MAX_FILENAME_SIZE]; - snprintf(readlink_buffer, MAX_FILENAME_SIZE, "/proc/self/fd/%d", - destination_fd); - r = readlink(readlink_buffer, dest_filename, - MAX_FILENAME_SIZE); - if (r < 0) { - /* readlink failed */ - result = -1; - pb_log("%s: failed: unable to obtain temporary filename" - "\n", __func__); - } - dest_filename[r] = '\0'; + + snprintf(readlink_buffer, MAX_FILENAME_SIZE, "/proc/self/fd/%d", + destination_fd); + r = readlink(readlink_buffer, dest_filename, MAX_FILENAME_SIZE); + if (r < 0) { + /* readlink failed */ + result = -1; + r = 0; + pb_log("%s: failed: unable to obtain temporary filename\n", + __func__); } + dest_filename[r] = '\0'; + *destination_file = talloc_strdup(ctx, dest_filename); +out: + talloc_free(buffer); fclose(source_handle); fclose(destination_handle); - - *destination_file = talloc_strdup(ctx, dest_filename); - + close(destination_fd); return result; } -- cgit v1.2.1