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Don't call crdup nor uifind under vnode lock.

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A locked vnode can get into the way of satisyfing malloc with M_WATOK.

This is a fixup to r268087.

Suggested by:	kib
MFC after:	1 week
This commit is contained in:
Mateusz Guzik 2014-07-07 14:03:30 +00:00
parent dbd849d868
commit 5e2554b7f8
1 changed files with 4 additions and 2 deletions
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6
sys/kern/kern_exec.c
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@ -718,11 +718,11 @@ do_execve(td, args, mac_p)
VOP_UNLOCK(imgp->vp, 0);
setugidsafety(td);
error = fdcheckstd(td);
vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
if (error != 0)
goto done1;
newcred = crdup(oldcred);
euip = uifind(attr.va_uid);
vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
PROC_LOCK(p);
/*
* Set the new credentials.
@ -766,7 +766,9 @@ do_execve(td, args, mac_p)
if (oldcred->cr_svuid != oldcred->cr_uid ||
oldcred->cr_svgid != oldcred->cr_gid) {
PROC_UNLOCK(p);
VOP_UNLOCK(imgp->vp, 0);
newcred = crdup(oldcred);
vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
PROC_LOCK(p);
change_svuid(newcred, newcred->cr_uid);
change_svgid(newcred, newcred->cr_gid);
@ -843,6 +845,7 @@ do_execve(td, args, mac_p)
SDT_PROBE(proc, kernel, , exec__success, args->fname, 0, 0, 0, 0);
VOP_UNLOCK(imgp->vp, 0);
done1:
/*
* Free any resources malloc'd earlier that we didn't use.
@ -851,7 +854,6 @@ do_execve(td, args, mac_p)
uifree(euip);
if (newcred != NULL)
crfree(oldcred);
VOP_UNLOCK(imgp->vp, 0);
/*
* Handle deferred decrement of ref counts.