While debugging some issues with quota I realized that it's possible to pass array with bogus dquot pointers from __dquot_initialize to dqput. This can happen if the initialisation of the dquot objects for an inode fail and the control flow is transferred to the out_put label. In case only the USR or GRP quota are initialised then the PRJ pointer in the "got" array would remain uninitialised. This will cause the NULL ptr check in dqput to pass but actually the pointer is going to be invalid. Eventually this would cause a GFP.
To fix this just zero out the got array Signed-off-by: Nikolay Borisov <[email protected]> --- fs/quota/dquot.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index ef0d64b2a6d9..a0ab58fd85ae 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -1408,6 +1408,8 @@ static int __dquot_initialize(struct inode *inode, int type) dquots = i_dquot(inode); + memset(got, 0, 3 * sizeof(struct dquot *)); + /* First get references to structures we might need. */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) { struct kqid qid; -- 2.5.0
