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authorJ. Bruce Fields <bfields@citi.umich.edu>2008-03-14 19:37:11 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-03-14 16:49:15 -0700
commitb663c6fd98c9cf586279db03cec3257c413efd00 (patch)
treef268ae9e706044f48d2f95fcb4841ce89c70cf4b /fs
parent9b89ca7a3847c0d5b1e86e83f4860a866f28a89b (diff)
downloadvexpress-lsk-b663c6fd98c9cf586279db03cec3257c413efd00.tar.gz
nfsd: fix oops on access from high-numbered ports
This bug was always here, but before my commit 6fa02839bf9412e18e77 ("recheck for secure ports in fh_verify"), it could only be triggered by failure of a kmalloc(). After that commit it could be triggered by a client making a request from a non-reserved port for access to an export marked "secure". (Exports are "secure" by default.) The result is a struct svc_export with a reference count one too low, resulting in likely oopses next time the export is accessed. The reference counting here is not straightforward; a later patch will clean up fh_verify(). Thanks to Lukas Hejtmanek for the bug report and followup. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Cc: Lukas Hejtmanek <xhejtman@ics.muni.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/nfsd/nfsfh.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index 1eb771d79cc..3e6b3f41ee1 100644
--- a/fs/nfsd/nfsfh.c
+++ b/fs/nfsd/nfsfh.c
@@ -232,6 +232,7 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
fhp->fh_dentry = dentry;
fhp->fh_export = exp;
nfsd_nr_verified++;
+ cache_get(&exp->h);
} else {
/*
* just rechecking permissions
@@ -241,6 +242,7 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
dprintk("nfsd: fh_verify - just checking\n");
dentry = fhp->fh_dentry;
exp = fhp->fh_export;
+ cache_get(&exp->h);
/*
* Set user creds for this exportpoint; necessary even
* in the "just checking" case because this may be a
@@ -252,8 +254,6 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
if (error)
goto out;
}
- cache_get(&exp->h);
-
error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
if (error)