From 3eb7c1bf06d8e174be44b21a046caf5eda02de86 Mon Sep 17 00:00:00 2001 From: John Baldwin Date: Mon, 27 Apr 2020 18:04:42 +0000 Subject: [PATCH] Don't run strcmp() against strings stored in user memory. Instead, copy the strings into a temporary buffer on the stack and run strcmp on the copies. Reviewed by: brooks, kib Obtained from: CheriBSD MFC after: 1 week Sponsored by: DARPA Differential Revision: https://reviews.freebsd.org/D24567 --- sys/dev/iscsi_initiator/isc_subr.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/sys/dev/iscsi_initiator/isc_subr.c b/sys/dev/iscsi_initiator/isc_subr.c index 24b4bb2807b..c6f9a4efdab 100644 --- a/sys/dev/iscsi_initiator/isc_subr.c +++ b/sys/dev/iscsi_initiator/isc_subr.c @@ -97,6 +97,9 @@ i_crc32c(const void *buf, size_t size, uint32_t crc) int i_setopt(isc_session_t *sp, isc_opt_t *opt) { + char buf[16]; + int error; + if(opt->maxRecvDataSegmentLength > 0) { sp->opt.maxRecvDataSegmentLength = opt->maxRecvDataSegmentLength; sdebug(2, "maxRecvDataSegmentLength=%d", sp->opt.maxRecvDataSegmentLength); @@ -138,15 +141,21 @@ i_setopt(isc_session_t *sp, isc_opt_t *opt) } if(opt->headerDigest != NULL) { - sdebug(2, "opt.headerDigest='%s'", opt->headerDigest); - if(strcmp(opt->headerDigest, "CRC32C") == 0) { + error = copyinstr(opt->headerDigest, buf, sizeof(buf), NULL); + if (error != 0) + return (error); + sdebug(2, "opt.headerDigest='%s'", buf); + if(strcmp(buf, "CRC32C") == 0) { sp->hdrDigest = (digest_t *)i_crc32c; sdebug(2, "opt.headerDigest set"); } } if(opt->dataDigest != NULL) { - sdebug(2, "opt.dataDigest='%s'", opt->headerDigest); - if(strcmp(opt->dataDigest, "CRC32C") == 0) { + error = copyinstr(opt->dataDigest, buf, sizeof(buf), NULL); + if (error != 0) + return (error); + sdebug(2, "opt.dataDigest='%s'", opt->dataDigest); + if(strcmp(buf, "CRC32C") == 0) { sp->dataDigest = (digest_t *)i_crc32c; sdebug(2, "opt.dataDigest set"); }