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| author |   Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-08-24 10:59:25 -0400 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-09-04 14:52:43 -0400 |
| commit | 21f498c2f73bd6150d82931f09965826dca0b5f2 (patch) | |
| tree | 40885b9d8d338c4f1890f384ad2894f465163e91 /fs | |
| parent | NFS: Fix a problem with the legacy binary mount code (diff) | |
| download | linux-dev-21f498c2f73bd6150d82931f09965826dca0b5f2.tar.xz linux-dev-21f498c2f73bd6150d82931f09965826dca0b5f2.zip | |
NFSv4: Fix range checking in __nfs4_get_acl_uncached and __nfs4_proc_set_acl
Ensure that the user supplied buffer size doesn't cause us to overflow
the 'pages' array.
Also fix up some confusion between the use of PAGE_SIZE and
PAGE_CACHE_SIZE when calculating buffer sizes. We're not using
the page cache for anything here.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/nfs/nfs4proc.c | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 86b4c7361036..6b94f2d52532 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -3653,11 +3653,11 @@ static inline int nfs4_server_supports_acls(struct nfs_server *server) && (server->acl_bitmask & ACL4_SUPPORT_DENY_ACL); } -/* Assuming that XATTR_SIZE_MAX is a multiple of PAGE_CACHE_SIZE, and that - * it's OK to put sizeof(void) * (XATTR_SIZE_MAX/PAGE_CACHE_SIZE) bytes on +/* Assuming that XATTR_SIZE_MAX is a multiple of PAGE_SIZE, and that + * it's OK to put sizeof(void) * (XATTR_SIZE_MAX/PAGE_SIZE) bytes on * the stack. */ -#define NFS4ACL_MAXPAGES (XATTR_SIZE_MAX >> PAGE_CACHE_SHIFT) +#define NFS4ACL_MAXPAGES DIV_ROUND_UP(XATTR_SIZE_MAX, PAGE_SIZE) static int buf_to_pages_noslab(const void *buf, size_t buflen, struct page **pages, unsigned int *pgbase) @@ -3668,7 +3668,7 @@ static int buf_to_pages_noslab(const void *buf, size_t buflen, spages = pages; do { - len = min_t(size_t, PAGE_CACHE_SIZE, buflen); + len = min_t(size_t, PAGE_SIZE, buflen); newpage = alloc_page(GFP_KERNEL); if (newpage == NULL) @@ -3782,17 +3782,16 @@ static ssize_t __nfs4_get_acl_uncached(struct inode *inode, void *buf, size_t bu .rpc_argp = &args, .rpc_resp = &res, }; - int ret = -ENOMEM, npages, i; + unsigned int npages = DIV_ROUND_UP(buflen, PAGE_SIZE); + int ret = -ENOMEM, i; size_t acl_len = 0; - npages = (buflen + PAGE_SIZE - 1) >> PAGE_SHIFT; /* As long as we're doing a round trip to the server anyway, * let's be prepared for a page of acl data. */ if (npages == 0) npages = 1; - - /* Add an extra page to handle the bitmap returned */ - npages++; + if (npages > ARRAY_SIZE(pages)) + return -ERANGE; for (i = 0; i < npages; i++) { pages[i] = alloc_page(GFP_KERNEL); @@ -3891,10 +3890,13 @@ static int __nfs4_proc_set_acl(struct inode *inode, const void *buf, size_t bufl .rpc_argp = &arg, .rpc_resp = &res, }; + unsigned int npages = DIV_ROUND_UP(buflen, PAGE_SIZE); int ret, i; if (!nfs4_server_supports_acls(server)) return -EOPNOTSUPP; + if (npages > ARRAY_SIZE(pages)) + return -ERANGE; i = buf_to_pages_noslab(buf, buflen, arg.acl_pages, &arg.acl_pgbase); if (i < 0) return i; |