Date: Wed, 22 Nov 2023 00:14:08 GMT From: Rick Macklem <rmacklem@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 2d8d914450da - stable/13 - nfscl: newnfs_copycred() cannot be called when a mutex is held Message-ID: <202311220014.3AM0E89L014344@gitrepo.freebsd.org>
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The branch stable/13 has been updated by rmacklem: URL: https://cgit.FreeBSD.org/src/commit/?id=2d8d914450da1f9b79a7b51c0970445fcd9f648f commit 2d8d914450da1f9b79a7b51c0970445fcd9f648f Author: Rick Macklem <rmacklem@FreeBSD.org> AuthorDate: 2023-11-06 22:25:30 +0000 Commit: Rick Macklem <rmacklem@FreeBSD.org> CommitDate: 2023-11-22 00:13:25 +0000 nfscl: newnfs_copycred() cannot be called when a mutex is held Since newnfs_copycred() calls crsetgroups() which in turn calls crextend() which might do a malloc(M_WAITOK), newnfs_copycred() cannot be called with a mutex held. Fortunately, the malloc() call is rarely done, since XU_GROUPS is 16 and the NFS client uses a maximum of 17 (only 17 groups will cause the malloc() to be called). Further, it is only a problem if the malloc() tries to sleep(). As such, this bug does not seem to have caused problems in practice. This patch fixes the one place in the NFS client where newnfs_copycred() is called while a mutex is held by moving the call to after where the mutex is released. Found by inspection while working on an experimental patch. (cherry picked from commit 501bdf3001190686bf55d9d333cb533858c2cf2f) --- sys/fs/nfsclient/nfs_clstate.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/sys/fs/nfsclient/nfs_clstate.c b/sys/fs/nfsclient/nfs_clstate.c index 3d516a33934f..9ab0a29e9c5d 100644 --- a/sys/fs/nfsclient/nfs_clstate.c +++ b/sys/fs/nfsclient/nfs_clstate.c @@ -528,6 +528,7 @@ nfscl_getstateid(vnode_t vp, u_int8_t *nfhp, int fhlen, u_int32_t mode, struct nfscldeleg *dp; struct nfsnode *np; struct nfsmount *nmp; + struct nfscred ncr; u_int8_t own[NFSV4CL_LOCKNAMELEN], lockown[NFSV4CL_LOCKNAMELEN]; int error; bool done; @@ -685,7 +686,7 @@ nfscl_getstateid(vnode_t vp, u_int8_t *nfhp, int fhlen, u_int32_t mode, * A read ahead or write behind is indicated by p == NULL. */ if (p == NULL) - newnfs_copycred(&op->nfso_cred, cred); + memcpy(&ncr, &op->nfso_cred, sizeof(ncr)); } /* @@ -699,6 +700,8 @@ nfscl_getstateid(vnode_t vp, u_int8_t *nfhp, int fhlen, u_int32_t mode, stateidp->other[1] = op->nfso_stateid.other[1]; stateidp->other[2] = op->nfso_stateid.other[2]; NFSUNLOCKCLSTATE(); + if (p == NULL) + newnfs_copycred(&ncr, cred); return (0); }
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