6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Arnd Bergmann arnd@arndb.de
[ Upstream commit b630c781bcf6ff87657146661816d0d30a902139 ]
I tried to fix the stack usage in this function a couple of years ago, but there is still a problem with the latest gcc versions in some configurations:
net/caif/cfctrl.c:553:1: error: the frame size of 1296 bytes is larger than 1280 bytes [-Werror=frame-larger-than=]
Reduce this once again, with a separate cfctrl_link_setup() function that holds the bulk of all the local variables. It also turns out that the param[] array that takes up a large portion of the stack is write-only and can be left out here.
Fixes: ce6289661b14 ("caif: reduce stack size with KASAN") Signed-off-by: Arnd Bergmann arnd@arndb.de Link: https://patch.msgid.link/20250620112244.3425554-1-arnd@kernel.org Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/caif/cfctrl.c | 294 +++++++++++++++++++++++----------------------- 1 file changed, 144 insertions(+), 150 deletions(-)
diff --git a/net/caif/cfctrl.c b/net/caif/cfctrl.c index 8480684f2762..10eeace2278b 100644 --- a/net/caif/cfctrl.c +++ b/net/caif/cfctrl.c @@ -351,17 +351,154 @@ int cfctrl_cancel_req(struct cflayer *layr, struct cflayer *adap_layer) return found; }
+static int cfctrl_link_setup(struct cfctrl *cfctrl, struct cfpkt *pkt, u8 cmdrsp) +{ + u8 len; + u8 linkid = 0; + enum cfctrl_srv serv; + enum cfctrl_srv servtype; + u8 endpoint; + u8 physlinkid; + u8 prio; + u8 tmp; + u8 *cp; + int i; + struct cfctrl_link_param linkparam; + struct cfctrl_request_info rsp, *req; + + memset(&linkparam, 0, sizeof(linkparam)); + + tmp = cfpkt_extr_head_u8(pkt); + + serv = tmp & CFCTRL_SRV_MASK; + linkparam.linktype = serv; + + servtype = tmp >> 4; + linkparam.chtype = servtype; + + tmp = cfpkt_extr_head_u8(pkt); + physlinkid = tmp & 0x07; + prio = tmp >> 3; + + linkparam.priority = prio; + linkparam.phyid = physlinkid; + endpoint = cfpkt_extr_head_u8(pkt); + linkparam.endpoint = endpoint & 0x03; + + switch (serv) { + case CFCTRL_SRV_VEI: + case CFCTRL_SRV_DBG: + if (CFCTRL_ERR_BIT & cmdrsp) + break; + /* Link ID */ + linkid = cfpkt_extr_head_u8(pkt); + break; + case CFCTRL_SRV_VIDEO: + tmp = cfpkt_extr_head_u8(pkt); + linkparam.u.video.connid = tmp; + if (CFCTRL_ERR_BIT & cmdrsp) + break; + /* Link ID */ + linkid = cfpkt_extr_head_u8(pkt); + break; + + case CFCTRL_SRV_DATAGRAM: + linkparam.u.datagram.connid = cfpkt_extr_head_u32(pkt); + if (CFCTRL_ERR_BIT & cmdrsp) + break; + /* Link ID */ + linkid = cfpkt_extr_head_u8(pkt); + break; + case CFCTRL_SRV_RFM: + /* Construct a frame, convert + * DatagramConnectionID + * to network format long and copy it out... + */ + linkparam.u.rfm.connid = cfpkt_extr_head_u32(pkt); + cp = (u8 *) linkparam.u.rfm.volume; + for (tmp = cfpkt_extr_head_u8(pkt); + cfpkt_more(pkt) && tmp != '\0'; + tmp = cfpkt_extr_head_u8(pkt)) + *cp++ = tmp; + *cp = '\0'; + + if (CFCTRL_ERR_BIT & cmdrsp) + break; + /* Link ID */ + linkid = cfpkt_extr_head_u8(pkt); + + break; + case CFCTRL_SRV_UTIL: + /* Construct a frame, convert + * DatagramConnectionID + * to network format long and copy it out... + */ + /* Fifosize KB */ + linkparam.u.utility.fifosize_kb = cfpkt_extr_head_u16(pkt); + /* Fifosize bufs */ + linkparam.u.utility.fifosize_bufs = cfpkt_extr_head_u16(pkt); + /* name */ + cp = (u8 *) linkparam.u.utility.name; + caif_assert(sizeof(linkparam.u.utility.name) + >= UTILITY_NAME_LENGTH); + for (i = 0; i < UTILITY_NAME_LENGTH && cfpkt_more(pkt); i++) { + tmp = cfpkt_extr_head_u8(pkt); + *cp++ = tmp; + } + /* Length */ + len = cfpkt_extr_head_u8(pkt); + linkparam.u.utility.paramlen = len; + /* Param Data */ + cp = linkparam.u.utility.params; + while (cfpkt_more(pkt) && len--) { + tmp = cfpkt_extr_head_u8(pkt); + *cp++ = tmp; + } + if (CFCTRL_ERR_BIT & cmdrsp) + break; + /* Link ID */ + linkid = cfpkt_extr_head_u8(pkt); + /* Length */ + len = cfpkt_extr_head_u8(pkt); + /* Param Data */ + cfpkt_extr_head(pkt, NULL, len); + break; + default: + pr_warn("Request setup, invalid type (%d)\n", serv); + return -1; + } + + rsp.cmd = CFCTRL_CMD_LINK_SETUP; + rsp.param = linkparam; + spin_lock_bh(&cfctrl->info_list_lock); + req = cfctrl_remove_req(cfctrl, &rsp); + + if (CFCTRL_ERR_BIT == (CFCTRL_ERR_BIT & cmdrsp) || + cfpkt_erroneous(pkt)) { + pr_err("Invalid O/E bit or parse error " + "on CAIF control channel\n"); + cfctrl->res.reject_rsp(cfctrl->serv.layer.up, 0, + req ? req->client_layer : NULL); + } else { + cfctrl->res.linksetup_rsp(cfctrl->serv.layer.up, linkid, + serv, physlinkid, + req ? req->client_layer : NULL); + } + + kfree(req); + + spin_unlock_bh(&cfctrl->info_list_lock); + + return 0; +} + static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt) { u8 cmdrsp; u8 cmd; - int ret = -1; - u8 len; - u8 param[255]; + int ret = 0; u8 linkid = 0; struct cfctrl *cfctrl = container_obj(layer); - struct cfctrl_request_info rsp, *req; -
cmdrsp = cfpkt_extr_head_u8(pkt); cmd = cmdrsp & CFCTRL_CMD_MASK; @@ -374,150 +511,7 @@ static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
switch (cmd) { case CFCTRL_CMD_LINK_SETUP: - { - enum cfctrl_srv serv; - enum cfctrl_srv servtype; - u8 endpoint; - u8 physlinkid; - u8 prio; - u8 tmp; - u8 *cp; - int i; - struct cfctrl_link_param linkparam; - memset(&linkparam, 0, sizeof(linkparam)); - - tmp = cfpkt_extr_head_u8(pkt); - - serv = tmp & CFCTRL_SRV_MASK; - linkparam.linktype = serv; - - servtype = tmp >> 4; - linkparam.chtype = servtype; - - tmp = cfpkt_extr_head_u8(pkt); - physlinkid = tmp & 0x07; - prio = tmp >> 3; - - linkparam.priority = prio; - linkparam.phyid = physlinkid; - endpoint = cfpkt_extr_head_u8(pkt); - linkparam.endpoint = endpoint & 0x03; - - switch (serv) { - case CFCTRL_SRV_VEI: - case CFCTRL_SRV_DBG: - if (CFCTRL_ERR_BIT & cmdrsp) - break; - /* Link ID */ - linkid = cfpkt_extr_head_u8(pkt); - break; - case CFCTRL_SRV_VIDEO: - tmp = cfpkt_extr_head_u8(pkt); - linkparam.u.video.connid = tmp; - if (CFCTRL_ERR_BIT & cmdrsp) - break; - /* Link ID */ - linkid = cfpkt_extr_head_u8(pkt); - break; - - case CFCTRL_SRV_DATAGRAM: - linkparam.u.datagram.connid = - cfpkt_extr_head_u32(pkt); - if (CFCTRL_ERR_BIT & cmdrsp) - break; - /* Link ID */ - linkid = cfpkt_extr_head_u8(pkt); - break; - case CFCTRL_SRV_RFM: - /* Construct a frame, convert - * DatagramConnectionID - * to network format long and copy it out... - */ - linkparam.u.rfm.connid = - cfpkt_extr_head_u32(pkt); - cp = (u8 *) linkparam.u.rfm.volume; - for (tmp = cfpkt_extr_head_u8(pkt); - cfpkt_more(pkt) && tmp != '\0'; - tmp = cfpkt_extr_head_u8(pkt)) - *cp++ = tmp; - *cp = '\0'; - - if (CFCTRL_ERR_BIT & cmdrsp) - break; - /* Link ID */ - linkid = cfpkt_extr_head_u8(pkt); - - break; - case CFCTRL_SRV_UTIL: - /* Construct a frame, convert - * DatagramConnectionID - * to network format long and copy it out... - */ - /* Fifosize KB */ - linkparam.u.utility.fifosize_kb = - cfpkt_extr_head_u16(pkt); - /* Fifosize bufs */ - linkparam.u.utility.fifosize_bufs = - cfpkt_extr_head_u16(pkt); - /* name */ - cp = (u8 *) linkparam.u.utility.name; - caif_assert(sizeof(linkparam.u.utility.name) - >= UTILITY_NAME_LENGTH); - for (i = 0; - i < UTILITY_NAME_LENGTH - && cfpkt_more(pkt); i++) { - tmp = cfpkt_extr_head_u8(pkt); - *cp++ = tmp; - } - /* Length */ - len = cfpkt_extr_head_u8(pkt); - linkparam.u.utility.paramlen = len; - /* Param Data */ - cp = linkparam.u.utility.params; - while (cfpkt_more(pkt) && len--) { - tmp = cfpkt_extr_head_u8(pkt); - *cp++ = tmp; - } - if (CFCTRL_ERR_BIT & cmdrsp) - break; - /* Link ID */ - linkid = cfpkt_extr_head_u8(pkt); - /* Length */ - len = cfpkt_extr_head_u8(pkt); - /* Param Data */ - cfpkt_extr_head(pkt, ¶m, len); - break; - default: - pr_warn("Request setup, invalid type (%d)\n", - serv); - goto error; - } - - rsp.cmd = cmd; - rsp.param = linkparam; - spin_lock_bh(&cfctrl->info_list_lock); - req = cfctrl_remove_req(cfctrl, &rsp); - - if (CFCTRL_ERR_BIT == (CFCTRL_ERR_BIT & cmdrsp) || - cfpkt_erroneous(pkt)) { - pr_err("Invalid O/E bit or parse error " - "on CAIF control channel\n"); - cfctrl->res.reject_rsp(cfctrl->serv.layer.up, - 0, - req ? req->client_layer - : NULL); - } else { - cfctrl->res.linksetup_rsp(cfctrl->serv. - layer.up, linkid, - serv, physlinkid, - req ? req-> - client_layer : NULL); - } - - kfree(req); - - spin_unlock_bh(&cfctrl->info_list_lock); - } + ret = cfctrl_link_setup(cfctrl, pkt, cmdrsp); break; case CFCTRL_CMD_LINK_DESTROY: linkid = cfpkt_extr_head_u8(pkt); @@ -544,9 +538,9 @@ static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt) break; default: pr_err("Unrecognized Control Frame\n"); + ret = -1; goto error; } - ret = 0; error: cfpkt_destroy(pkt); return ret;