mmap will fail with SIGBUS if trying to map a non-existent portion of a file. While this should never happen with /dev/mem, it can happen if passing a regular file with option -d. While people should no longer do that, failure gracefully seems better than crashing. So check for the file size before calling mmap.
This closes bug #46066: http://savannah.nongnu.org/bugs/?46066 --- util.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) --- dmidecode.orig/util.c 2015-09-29 11:27:02.136566009 +0200 +++ dmidecode/util.c 2015-09-29 11:37:24.746191083 +0200 @@ -152,6 +152,7 @@ void *mem_chunk(off_t base, size_t len, void *p; int fd; #ifdef USE_MMAP + struct stat statbuf; off_t mmoffset; void *mmp; #endif @@ -169,6 +170,26 @@ void *mem_chunk(off_t base, size_t len, } #ifdef USE_MMAP + if (fstat(fd, &statbuf) == -1) + { + fprintf(stderr, "%s: ", devmem); + perror("stat"); + free(p); + return NULL; + } + + /* + * mmap() will fail with SIGBUS if trying to map beyond the end of + * the file. + */ + if (S_ISREG(statbuf.st_mode) && base + (off_t)len > statbuf.st_size) + { + fprintf(stderr, "mmap: Can't map beyond end of file %s\n", + devmem); + free(p); + return NULL; + } + #ifdef _SC_PAGESIZE mmoffset = base % sysconf(_SC_PAGESIZE); #else -- Jean Delvare SUSE L3 Support _______________________________________________ https://lists.nongnu.org/mailman/listinfo/dmidecode-devel
