3.0-stable review patch. If anyone has any objections, please let me know.
------------------ From: Trond Myklebust <[email protected]> commit 331818f1c468a24e581aedcbe52af799366a9dfe upstream. Commit bf118a342f10dafe44b14451a1392c3254629a1f (NFSv4: include bitmap in nfsv4 get acl data) introduces the 'acl_scratch' page for the case where we may need to decode multi-page data. However it fails to take into account the fact that the variable may be NULL (for the case where we're not doing multi-page decode), and it also attaches it to the encoding xdr_stream rather than the decoding one. The immediate result is an Oops in nfs4_xdr_enc_getacl due to the call to page_address() with a NULL page pointer. Signed-off-by: Trond Myklebust <[email protected]> Cc: Andy Adamson <[email protected]> Signed-off-by: Jiri Slaby <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/nfs/nfs4proc.c | 8 ++++---- fs/nfs/nfs4xdr.c | 5 ++++- include/linux/nfs_xdr.h | 2 +- 3 files changed, 9 insertions(+), 6 deletions(-) --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -3578,8 +3578,8 @@ static ssize_t __nfs4_get_acl_uncached(s } if (npages > 1) { /* for decoding across pages */ - args.acl_scratch = alloc_page(GFP_KERNEL); - if (!args.acl_scratch) + res.acl_scratch = alloc_page(GFP_KERNEL); + if (!res.acl_scratch) goto out_free; } args.acl_len = npages * PAGE_SIZE; @@ -3615,8 +3615,8 @@ out_free: for (i = 0; i < npages; i++) if (pages[i]) __free_page(pages[i]); - if (args.acl_scratch) - __free_page(args.acl_scratch); + if (res.acl_scratch) + __free_page(res.acl_scratch); return ret; } --- a/fs/nfs/nfs4xdr.c +++ b/fs/nfs/nfs4xdr.c @@ -2379,7 +2379,6 @@ static void nfs4_xdr_enc_getacl(struct r xdr_inline_pages(&req->rq_rcv_buf, replen << 2, args->acl_pages, args->acl_pgbase, args->acl_len); - xdr_set_scratch_buffer(xdr, page_address(args->acl_scratch), PAGE_SIZE); encode_nops(&hdr); } @@ -5688,6 +5687,10 @@ nfs4_xdr_dec_getacl(struct rpc_rqst *rqs struct compound_hdr hdr; int status; + if (res->acl_scratch != NULL) { + void *p = page_address(res->acl_scratch); + xdr_set_scratch_buffer(xdr, p, PAGE_SIZE); + } status = decode_compound_hdr(xdr, &hdr); if (status) goto out; --- a/include/linux/nfs_xdr.h +++ b/include/linux/nfs_xdr.h @@ -588,7 +588,6 @@ struct nfs_getaclargs { size_t acl_len; unsigned int acl_pgbase; struct page ** acl_pages; - struct page * acl_scratch; struct nfs4_sequence_args seq_args; }; @@ -598,6 +597,7 @@ struct nfs_getaclres { size_t acl_len; size_t acl_data_offset; int acl_flags; + struct page * acl_scratch; struct nfs4_sequence_res seq_res; }; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
