commit: 32b007b4e19b50ff4d27ea8b69cd6d744cfec86b From: J. Bruce Fields <[email protected]> Date: Sun, 6 Mar 2011 19:11:03 -0500 Subject: [PATCH] nfsd4: fix bad pointer on failure to find delegation
In case of a nonempty list, the return on error here is obviously bogus; it ends up being a pointer to the list head instead of to any valid delegation on the list. In particular, if nfsd4_delegreturn() hits this case, and you're quite unlucky, then renew_client may oops, and it may take an embarassingly long time to figure out why. Facepalm. BUG: unable to handle kernel NULL pointer dereference at 0000000000000090 IP: [<ffffffff81292965>] nfsd4_delegreturn+0x125/0x200 .. Cc: [email protected] Signed-off-by: J. Bruce Fields <[email protected]> --- fs/nfsd/nfs4state.c | 13 +++++++------ 1 files changed, 7 insertions(+), 6 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 54b60bf..7b566ec 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -2445,15 +2445,16 @@ nfs4_check_delegmode(struct nfs4_delegation *dp, int flags) static struct nfs4_delegation * find_delegation_file(struct nfs4_file *fp, stateid_t *stid) { - struct nfs4_delegation *dp = NULL; + struct nfs4_delegation *dp; spin_lock(&recall_lock); - list_for_each_entry(dp, &fp->fi_delegations, dl_perfile) { - if (dp->dl_stateid.si_stateownerid == stid->si_stateownerid) - break; - } + list_for_each_entry(dp, &fp->fi_delegations, dl_perfile) + if (dp->dl_stateid.si_stateownerid == stid->si_stateownerid) { + spin_unlock(&recall_lock); + return dp; + } spin_unlock(&recall_lock); - return dp; + return NULL; } int share_access_to_flags(u32 share_access) _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
