Author: cem Date: Fri Dec 16 01:59:28 2016 New Revision: 310142 URL: https://svnweb.freebsd.org/changeset/base/310142
Log: ktrdump(8): Capsicumify We restrict the (optional) input file and output files. It would be nice to restrict the KVM files, but that's up to libkvm. We wait until after kvm_nlist() is invoked to cap_enter() because kldsym() isn't supported in the Capsicum sandbox. Feedback from: emaste@ (earlier versions) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D7921 Modified: head/usr.bin/ktrdump/ktrdump.c Modified: head/usr.bin/ktrdump/ktrdump.c ============================================================================== --- head/usr.bin/ktrdump/ktrdump.c Fri Dec 16 01:51:12 2016 (r310141) +++ head/usr.bin/ktrdump/ktrdump.c Fri Dec 16 01:59:28 2016 (r310142) @@ -29,11 +29,14 @@ __FBSDID("$FreeBSD$"); #include <sys/types.h> +#include <sys/capsicum.h> #include <sys/ktr.h> #include <sys/mman.h> #include <sys/stat.h> +#include <capsicum_helpers.h> #include <err.h> +#include <errno.h> #include <fcntl.h> #include <kvm.h> #include <limits.h> @@ -70,6 +73,7 @@ static int hflag; static char corefile[PATH_MAX]; static char execfile[PATH_MAX]; +static char outfile[PATH_MAX] = "stdout"; static char desc[SBUFLEN]; static char errbuf[_POSIX2_LINE_MAX]; @@ -87,6 +91,7 @@ main(int ac, char **av) struct ktr_entry *buf; uintmax_t tlast, tnow; unsigned long bufptr; + cap_rights_t rights; struct stat sb; kvm_t *kd; FILE *out; @@ -122,6 +127,11 @@ main(int ac, char **av) iflag = 1; if ((in = open(optarg, O_RDONLY)) == -1) err(1, "%s", optarg); + cap_rights_init(&rights, CAP_FSTAT, CAP_MMAP_R); + if (cap_rights_limit(in, &rights) < 0 && + errno != ENOSYS) + err(1, "unable to limit rights for %s", + optarg); break; case 'M': case 'm': @@ -133,6 +143,7 @@ main(int ac, char **av) case 'o': if ((out = fopen(optarg, "w")) == NULL) err(1, "%s", optarg); + strlcpy(outfile, optarg, sizeof(outfile)); break; case 'q': qflag++; @@ -155,6 +166,10 @@ main(int ac, char **av) if (ac != 0) usage(); + cap_rights_init(&rights, CAP_FSTAT, CAP_WRITE); + if (cap_rights_limit(fileno(out), &rights) < 0 && errno != ENOSYS) + err(1, "unable to limit rights for %s", outfile); + /* * Open our execfile and corefile, resolve needed symbols and read in * the trace buffer. @@ -162,11 +177,28 @@ main(int ac, char **av) if ((kd = kvm_openfiles(Nflag ? execfile : NULL, Mflag ? corefile : NULL, NULL, O_RDONLY, errbuf)) == NULL) errx(1, "%s", errbuf); + + /* + * Cache NLS data, for strerror, for err(3), before entering capability + * mode. + */ + caph_cache_catpages(); + if (kvm_nlist(kd, nl) != 0 || kvm_read(kd, nl[0].n_value, &version, sizeof(version)) == -1) errx(1, "%s", kvm_geterr(kd)); if (version != KTR_VERSION) errx(1, "ktr version mismatch"); + + /* + * Enter Capsicum sandbox. + * + * kvm_nlist() above uses kldsym(2) for native kernels, and that isn't + * allowed in the sandbox. + */ + if (cap_enter() < 0 && errno != ENOSYS) + err(1, "unable to enter capability mode"); + if (iflag) { if (fstat(in, &sb) == -1) errx(1, "stat"); _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
