From 68eb64c3d2fd558c606dcff6d3e8a2701388a80f Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 4 Oct 2018 09:32:27 +0100 Subject: afs: Do better max capacity handling on address lists Note the maximum allocated capacity in an afs_addr_list struct and discard addresses that would exceed it in afs_merge_fs_addr{4,6}(). Also, since the current maximum capacity is less than 255, reduce the relevant members to bytes. Signed-off-by: David Howells --- fs/afs/addr_list.c | 19 +++++++++++-------- fs/afs/internal.h | 8 +++++--- 2 files changed, 16 insertions(+), 11 deletions(-) (limited to 'fs/afs') diff --git a/fs/afs/addr_list.c b/fs/afs/addr_list.c index 025a9a5e1c32..4dbb8af54668 100644 --- a/fs/afs/addr_list.c +++ b/fs/afs/addr_list.c @@ -17,11 +17,6 @@ #include "internal.h" #include "afs_fs.h" -//#define AFS_MAX_ADDRESSES -// ((unsigned int)((PAGE_SIZE - sizeof(struct afs_addr_list)) / -// sizeof(struct sockaddr_rxrpc))) -#define AFS_MAX_ADDRESSES ((unsigned int)(sizeof(unsigned long) * 8)) - /* * Release an address list. */ @@ -43,11 +38,15 @@ struct afs_addr_list *afs_alloc_addrlist(unsigned int nr, _enter("%u,%u,%u", nr, service, port); + if (nr > AFS_MAX_ADDRESSES) + nr = AFS_MAX_ADDRESSES; + alist = kzalloc(struct_size(alist, addrs, nr), GFP_KERNEL); if (!alist) return NULL; refcount_set(&alist->usage, 1); + alist->max_addrs = nr; for (i = 0; i < nr; i++) { struct sockaddr_rxrpc *srx = &alist->addrs[i]; @@ -109,8 +108,6 @@ struct afs_addr_list *afs_parse_text_addrs(const char *text, size_t len, } while (p < end); _debug("%u/%u addresses", nr, AFS_MAX_ADDRESSES); - if (nr > AFS_MAX_ADDRESSES) - nr = AFS_MAX_ADDRESSES; alist = afs_alloc_addrlist(nr, service, port); if (!alist) @@ -180,7 +177,7 @@ struct afs_addr_list *afs_parse_text_addrs(const char *text, size_t len, } alist->nr_addrs++; - } while (p < end && alist->nr_addrs < AFS_MAX_ADDRESSES); + } while (p < end && alist->nr_addrs < alist->max_addrs); _leave(" = [nr %u]", alist->nr_addrs); return alist; @@ -241,6 +238,9 @@ void afs_merge_fs_addr4(struct afs_addr_list *alist, __be32 xdr, u16 port) __be16 xport = htons(port); int i; + if (alist->nr_addrs >= alist->max_addrs) + return; + for (i = 0; i < alist->nr_ipv4; i++) { a = &alist->addrs[i].transport.sin6; if (xdr == a->sin6_addr.s6_addr32[3] && @@ -277,6 +277,9 @@ void afs_merge_fs_addr6(struct afs_addr_list *alist, __be32 *xdr, u16 port) __be16 xport = htons(port); int i, diff; + if (alist->nr_addrs >= alist->max_addrs) + return; + for (i = alist->nr_ipv4; i < alist->nr_addrs; i++) { a = &alist->addrs[i].transport.sin6; diff = memcmp(xdr, &a->sin6_addr, 16); diff --git a/fs/afs/internal.h b/fs/afs/internal.h index 871a228d7f37..8ae4e2ebb99a 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -73,12 +73,14 @@ struct afs_addr_list { struct rcu_head rcu; /* Must be first */ refcount_t usage; u32 version; /* Version */ - unsigned short nr_addrs; - unsigned short index; /* Address currently in use */ - unsigned short nr_ipv4; /* Number of IPv4 addresses */ + unsigned char max_addrs; + unsigned char nr_addrs; + unsigned char index; /* Address currently in use */ + unsigned char nr_ipv4; /* Number of IPv4 addresses */ unsigned long probed; /* Mask of servers that have been probed */ unsigned long yfs; /* Mask of servers that are YFS */ struct sockaddr_rxrpc addrs[]; +#define AFS_MAX_ADDRESSES ((unsigned int)(sizeof(unsigned long) * 8)) }; /* -- cgit v1.2.3