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rpc: gss: fix a kmap_atomic race in krb5 code

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This code is never called from interrupt context; it's always run by either
a user thread or rpciod.  So KM_SKB_SUNRPC_DATA is inappropriate here.

Thanks to Aimé Le Rouzic for capturing an oops which showed the kernel
taking an interrupt while we were in this piece of code, resulting in a
nested kmap_atomic(.,KM_SKB_SUNRPC_DATA) call from
xdr_partial_copy_from_skb().

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
J. Bruce Fields 2006-12-04 20:22:32 -05:00 committed by Trond Myklebust
parent 8fc7500bb8
commit 87d918d667
1 changed files with 2 additions and 2 deletions
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4
net/sunrpc/auth_gss/gss_krb5_wrap.c
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@ -57,9 +57,9 @@ gss_krb5_remove_padding(struct xdr_buf *buf, int blocksize)
>>PAGE_CACHE_SHIFT;
int offset = (buf->page_base + len - 1)
& (PAGE_CACHE_SIZE - 1);
ptr = kmap_atomic(buf->pages[last], KM_SKB_SUNRPC_DATA);
ptr = kmap_atomic(buf->pages[last], KM_USER0);
pad = *(ptr + offset);
kunmap_atomic(ptr, KM_SKB_SUNRPC_DATA);
kunmap_atomic(ptr, KM_USER0);
goto out;
} else
len -= buf->page_len;