From 502aa0cb17507c7af0cca61aeb5ff17b65c7afc7 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 6 Jul 2018 17:56:57 +0200 Subject: [PATCH 23/89] pr-helper: avoid error on PR IN command with zero request size RH-Author: Paolo Bonzini Message-id: <20180706175659.30615-8-pbonzini@redhat.com> Patchwork-id: 81250 O-Subject: [RHEL7.6 qemu-kvm-rhev PATCH 7/9] pr-helper: avoid error on PR IN command with zero request size Bugzilla: 1533158 RH-Acked-by: Laurent Vivier RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Michal Privoznik After reading a PR IN command with zero request size in prh_read_request, the resp->result field will be uninitialized and the resp.sz field will be also uninitialized when returning to prh_co_entry. If resp->result == GOOD (from a previous successful reply or just luck), then the assert in prh_write_response might not be triggered and uninitialized response will be sent. The fix is to remove the whole handling of sz == 0 in prh_co_entry. Those errors apply only to PR OUT commands and it's perfectly okay to catch them later in do_pr_out and multipath_pr_out; the check for too-short parameters in fact doesn't apply in the easy SG_IO case, as it can be left to the target firmware even. The result is that prh_read_request does not fail requests anymore and prh_co_entry becomes simpler. Reported-by: Dima Stepanov Signed-off-by: Paolo Bonzini (cherry picked from commit ee8c13b81474e002db083e9692b11c0e106a9c7f) Signed-off-by: Miroslav Rezanina --- scsi/qemu-pr-helper.c | 63 ++++++++++++++++++++++++--------------------------- 1 file changed, 30 insertions(+), 33 deletions(-) diff --git a/scsi/qemu-pr-helper.c b/scsi/qemu-pr-helper.c index 3961023..4d843bd 100644 --- a/scsi/qemu-pr-helper.c +++ b/scsi/qemu-pr-helper.c @@ -444,6 +444,14 @@ static int multipath_pr_out(int fd, const uint8_t *cdb, uint8_t *sense, char transportids[PR_HELPER_DATA_SIZE]; int r; + if (sz < PR_OUT_FIXED_PARAM_SIZE) { + /* Illegal request, Parameter list length error. This isn't fatal; + * we have read the data, send an error without closing the socket. + */ + scsi_build_sense(sense, SENSE_CODE(INVALID_PARAM_LEN)); + return CHECK_CONDITION; + } + switch (rq_servact) { case MPATH_PROUT_REG_SA: case MPATH_PROUT_RES_SA: @@ -563,6 +571,12 @@ static int do_pr_out(int fd, const uint8_t *cdb, uint8_t *sense, const uint8_t *param, int sz) { int resp_sz; + + if ((fcntl(fd, F_GETFL) & O_ACCMODE) == O_RDONLY) { + scsi_build_sense(sense, SENSE_CODE(INVALID_OPCODE)); + return CHECK_CONDITION; + } + #ifdef CONFIG_MPATH if (is_mpath(fd)) { return multipath_pr_out(fd, cdb, sense, param, sz); @@ -679,21 +693,6 @@ static int coroutine_fn prh_read_request(PRHelperClient *client, errp) < 0) { goto out_close; } - if ((fcntl(client->fd, F_GETFL) & O_ACCMODE) == O_RDONLY) { - scsi_build_sense(resp->sense, SENSE_CODE(INVALID_OPCODE)); - sz = 0; - } else if (sz < PR_OUT_FIXED_PARAM_SIZE) { - /* Illegal request, Parameter list length error. This isn't fatal; - * we have read the data, send an error without closing the socket. - */ - scsi_build_sense(resp->sense, SENSE_CODE(INVALID_PARAM_LEN)); - sz = 0; - } - if (sz == 0) { - resp->result = CHECK_CONDITION; - close(client->fd); - client->fd = -1; - } } req->fd = client->fd; @@ -774,25 +773,23 @@ static void coroutine_fn prh_co_entry(void *opaque) break; } - if (sz > 0) { - num_active_sockets++; - if (req.cdb[0] == PERSISTENT_RESERVE_OUT) { - r = do_pr_out(req.fd, req.cdb, resp.sense, - client->data, sz); - resp.sz = 0; - } else { - resp.sz = sizeof(client->data); - r = do_pr_in(req.fd, req.cdb, resp.sense, - client->data, &resp.sz); - resp.sz = MIN(resp.sz, sz); - } - num_active_sockets--; - close(req.fd); - if (r == -1) { - break; - } - resp.result = r; + num_active_sockets++; + if (req.cdb[0] == PERSISTENT_RESERVE_OUT) { + r = do_pr_out(req.fd, req.cdb, resp.sense, + client->data, sz); + resp.sz = 0; + } else { + resp.sz = sizeof(client->data); + r = do_pr_in(req.fd, req.cdb, resp.sense, + client->data, &resp.sz); + resp.sz = MIN(resp.sz, sz); + } + num_active_sockets--; + close(req.fd); + if (r == -1) { + break; } + resp.result = r; if (prh_write_response(client, &req, &resp, &local_err) < 0) { break; -- 1.8.3.1