The branch stable/12 has been updated by mav:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=ce1895b7248d5601b34d0d6492539a7081a8d451

commit ce1895b7248d5601b34d0d6492539a7081a8d451
Author:     Alexander Motin <[email protected]>
AuthorDate: 2022-09-07 01:58:27 +0000
Commit:     Alexander Motin <[email protected]>
CommitDate: 2022-09-14 17:28:18 +0000

    CTL: Validate IOCTL parameters.
    
    It was possible to cause kernel panic by passing too large args_len
    or non-NULL result_nvl.
    
    Though since the /dev/cam/ctl device is accessible only by root and
    used only by limited number of tools it was not a big problem.
    
    PR:     266115
    PR:     266136
    Reported by:    Robert Morris <[email protected]>
    MFC after:      1 week
    
    (cherry picked from commit 0586be48a97c5af50ba4f578d33211f81cc57016)
---
 sys/cam/ctl/ctl.c       | 14 ++++++++++++++
 sys/cam/ctl/ctl_ioctl.h |  1 +
 2 files changed, 15 insertions(+)

diff --git a/sys/cam/ctl/ctl.c b/sys/cam/ctl/ctl.c
index e909ccf70406..e0f30ebe1250 100644
--- a/sys/cam/ctl/ctl.c
+++ b/sys/cam/ctl/ctl.c
@@ -2904,6 +2904,12 @@ ctl_ioctl(struct cdev *dev, u_long cmd, caddr_t addr, 
int flag,
                }
 
                if (lun_req->args != NULL) {
+                       if (lun_req->args_len > CTL_MAX_ARGS_LEN) {
+                               lun_req->status = CTL_LUN_ERROR;
+                               snprintf(lun_req->error_str, 
sizeof(lun_req->error_str),
+                                   "Too big args.");
+                               break;
+                       }
                        packed = malloc(lun_req->args_len, M_CTL, M_WAITOK);
                        if (copyin(lun_req->args, packed, lun_req->args_len) != 
0) {
                                free(packed, M_CTL);
@@ -2925,6 +2931,7 @@ ctl_ioctl(struct cdev *dev, u_long cmd, caddr_t addr, int 
flag,
                } else
                        lun_req->args_nvl = nvlist_create(0);
 
+               lun_req->result_nvl = NULL;
                retval = backend->ioctl(dev, cmd, addr, flag, td);
                nvlist_destroy(lun_req->args_nvl);
                lun_req->args_nvl = tmp_args_nvl;
@@ -3181,6 +3188,12 @@ ctl_ioctl(struct cdev *dev, u_long cmd, caddr_t addr, 
int flag,
                }
 
                if (req->args != NULL) {
+                       if (req->args_len > CTL_MAX_ARGS_LEN) {
+                               req->status = CTL_LUN_ERROR;
+                               snprintf(req->error_str, sizeof(req->error_str),
+                                   "Too big args.");
+                               break;
+                       }
                        packed = malloc(req->args_len, M_CTL, M_WAITOK);
                        if (copyin(req->args, packed, req->args_len) != 0) {
                                free(packed, M_CTL);
@@ -3202,6 +3215,7 @@ ctl_ioctl(struct cdev *dev, u_long cmd, caddr_t addr, int 
flag,
                } else
                        req->args_nvl = nvlist_create(0);
 
+               req->result_nvl = NULL;
                if (fe->ioctl)
                        retval = fe->ioctl(dev, cmd, addr, flag, td);
                else
diff --git a/sys/cam/ctl/ctl_ioctl.h b/sys/cam/ctl/ctl_ioctl.h
index 49c48afbd766..e9caa3f0982b 100644
--- a/sys/cam/ctl/ctl_ioctl.h
+++ b/sys/cam/ctl/ctl_ioctl.h
@@ -460,6 +460,7 @@ struct ctl_lun_req {
        union ctl_lunreq_data   reqdata;
        void *                  args;
        nvlist_t *              args_nvl;
+#define        CTL_MAX_ARGS_LEN        (1024 * 1024)
        size_t                  args_len;
        void *                  result;
        nvlist_t *              result_nvl;

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