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nfsd: put dl_stid if fail to queue dl_recall

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commit 230ca758453c63bd38e4d9f4a21db698f7abada8 upstream.

Before calling nfsd4_run_cb to queue dl_recall to the callback_wq, we
increment the reference count of dl_stid.
We expect that after the corresponding work_struct is processed, the
reference count of dl_stid will be decremented through the callback
function nfsd4_cb_recall_release.
However, if the call to nfsd4_run_cb fails, the incremented reference
count of dl_stid will not be decremented correspondingly, leading to the
following nfs4_stid leak:
unreferenced object 0xffff88812067b578 (size 344):
  comm "nfsd", pid 2761, jiffies 4295044002 (age 5541.241s)
  hex dump (first 32 bytes):
    01 00 00 00 6b 6b 6b 6b b8 02 c0 e2 81 88 ff ff  ....kkkk........
    00 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 ad 4e ad de  .kkkkkkk.....N..
  backtrace:
    kmem_cache_alloc+0x4b9/0x700
    nfsd4_process_open1+0x34/0x300
    nfsd4_open+0x2d1/0x9d0
    nfsd4_proc_compound+0x7a2/0xe30
    nfsd_dispatch+0x241/0x3e0
    svc_process_common+0x5d3/0xcc0
    svc_process+0x2a3/0x320
    nfsd+0x180/0x2e0
    kthread+0x199/0x1d0
    ret_from_fork+0x30/0x50
    ret_from_fork_asm+0x1b/0x30
unreferenced object 0xffff8881499f4d28 (size 368):
  comm "nfsd", pid 2761, jiffies 4295044005 (age 5541.239s)
  hex dump (first 32 bytes):
    01 00 00 00 00 00 00 00 30 4d 9f 49 81 88 ff ff  ........0M.I....
    30 4d 9f 49 81 88 ff ff 20 00 00 00 01 00 00 00  0M.I.... .......
  backtrace:
    kmem_cache_alloc+0x4b9/0x700
    nfs4_alloc_stid+0x29/0x210
    alloc_init_deleg+0x92/0x2e0
    nfs4_set_delegation+0x284/0xc00
    nfs4_open_delegation+0x216/0x3f0
    nfsd4_process_open2+0x2b3/0xee0
    nfsd4_open+0x770/0x9d0
    nfsd4_proc_compound+0x7a2/0xe30
    nfsd_dispatch+0x241/0x3e0
    svc_process_common+0x5d3/0xcc0
    svc_process+0x2a3/0x320
    nfsd+0x180/0x2e0
    kthread+0x199/0x1d0
    ret_from_fork+0x30/0x50
    ret_from_fork_asm+0x1b/0x30
Fix it by checking the result of nfsd4_run_cb and call nfs4_put_stid if
fail to queue dl_recall.

Cc: stable@vger.kernel.org
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Li Lingfeng 2025-02-13 22:42:20 +08:00 committed by Greg Kroah-Hartman
parent 30ef7cfee7
commit d96587cc93
1 changed files with 11 additions and 1 deletions
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12
fs/nfsd/nfs4state.c
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@ -1069,6 +1069,12 @@ static struct nfs4_ol_stateid * nfs4_alloc_open_stateid(struct nfs4_client *clp)
return openlockstateid(stid);
}
/*
* As the sc_free callback of deleg, this may be called by nfs4_put_stid
* in nfsd_break_one_deleg.
* Considering nfsd_break_one_deleg is called with the flc->flc_lock held,
* this function mustn't ever sleep.
*/
static void nfs4_free_deleg(struct nfs4_stid *stid)
{
struct nfs4_delegation *dp = delegstateid(stid);
@ -4923,6 +4929,7 @@ static const struct nfsd4_callback_ops nfsd4_cb_recall_ops = {
static void nfsd_break_one_deleg(struct nfs4_delegation *dp)
{
bool queued;
/*
* We're assuming the state code never drops its reference
* without first removing the lease. Since we're in this lease
@ -4931,7 +4938,10 @@ static void nfsd_break_one_deleg(struct nfs4_delegation *dp)
* we know it's safe to take a reference.
*/
refcount_inc(&dp->dl_stid.sc_count);
WARN_ON_ONCE(!nfsd4_run_cb(&dp->dl_recall));
queued = nfsd4_run_cb(&dp->dl_recall);
WARN_ON_ONCE(!queued);
if (!queued)
nfs4_put_stid(&dp->dl_stid);
}
/* Called from break_lease() with flc_lock held. */