svn commit: r364486 - head/sys/kern

[Mateusz Guzik]

Author: mjg
Date: Sat Aug 22 16:57:45 2020
New Revision: 364486
URL: https://svnweb.freebsd.org/changeset/base/364486

Log:
  fd: pwd_drop after releasing filedesc lock
  
  Fixes a potential LOR against vnode lock.

Modified:
  head/sys/kern/kern_descrip.c

Modified: head/sys/kern/kern_descrip.c
==============================================================================
--- head/sys/kern/kern_descrip.c	Sat Aug 22 15:31:56 2020	(r364485)
+++ head/sys/kern/kern_descrip.c	Sat Aug 22 16:57:45 2020	(r364486)
@@ -3957,7 +3957,6 @@ kern_proc_filedesc_out(struct proc *p,  struct sbuf *s
 			vrefact(pwd->pwd_jdir);
 			export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf);
 		}
-		pwd_drop(pwd);
 	}
 	lastfile = fdlastfile(fdp);
 	for (i = 0; fdp->fd_refcnt > 0 && i <= lastfile; i++) {
@@ -3979,6 +3978,8 @@ kern_proc_filedesc_out(struct proc *p,  struct sbuf *s
 			break;
 	}
 	FILEDESC_SUNLOCK(fdp);
+	if (pwd != NULL)
+		pwd_drop(pwd);
 	fddrop(fdp);
 fail:
 	free(efbuf, M_TEMP);
@@ -4100,7 +4101,6 @@ sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS)
 		if (pwd->pwd_jdir != NULL)
 			export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif,
 			    okif, fdp, req);
-		pwd_drop(pwd);
 	}
 	lastfile = fdlastfile(fdp);
 	for (i = 0; fdp->fd_refcnt > 0 && i <= lastfile; i++) {
@@ -4116,6 +4116,8 @@ sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS)
 			break;
 	}
 	FILEDESC_SUNLOCK(fdp);
+	if (pwd != NULL)
+		pwd_drop(pwd);
 	fddrop(fdp);
 	free(kif, M_TEMP);
 	free(okif, M_TEMP);