From: NeilBrown Date: Tue, 11 Apr 2006 05:55:27 +0000 (-0700) Subject: [PATCH] knfsd: nfsd: oops exporting nonexistent directory X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=cd15654963cf7e4dd938a403de3ec5bcd09f8350;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git [PATCH] knfsd: nfsd: oops exporting nonexistent directory Export a directory that does not exist: exportfs -orw,fsid=0,insecure,no_subtree_check client:/home/NFS4 Try to mount from client with nfs4. Mount hangs (I'm not sure why - that's another issue). While client is hung, back on server mkdir /home/NFS4 The server panics in dput. I traced the problem back to svc_export_parse() calling path_release() even though path_lookup() failed (it happens to fill in the nameidata structure with a negative dentry - so the test after out: succeeds). After patching, an recreating the problem, the client mount still takes some time before finally exiting with a message "couldn't read superblock". Here is a simple patch to resolve this issue: Signed-off-by: Frank Filz Signed-off-by: J. Bruce Fields Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c index c340be0a3f5..4e0578121d9 100644 --- a/fs/nfsd/export.c +++ b/fs/nfsd/export.c @@ -422,7 +422,7 @@ static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen) if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0) goto out; err = path_lookup(buf, 0, &nd); - if (err) goto out; + if (err) goto out_no_path; exp.h.flags = 0; exp.ex_client = dom; @@ -475,6 +475,7 @@ static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen) out: if (nd.dentry) path_release(&nd); + out_no_path: if (dom) auth_domain_put(dom); kfree(buf);