diff options
| author | holt@sgi.com <holt@sgi.com> | 2010-10-20 02:03:37 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-11-22 11:00:11 -0800 |
| commit | 56b8700a1069f66ace7575b9cd104f626379f8cd (patch) | |
| tree | fabdab952620154111cd47c0cc1f3d413b6adf9d /net | |
| parent | 44f89254e4ce18795b2b7b9d1f722e0f6ac4711c (diff) | |
Limit sysctl_tcp_mem and sysctl_udp_mem initializers to prevent integer overflows.
On a 16TB x86_64 machine, sysctl_tcp_mem[2], sysctl_udp_mem[2], and
sysctl_sctp_mem[2] can integer overflow. Set limit such that they are
maximized without overflowing.
Signed-off-by: Robin Holt <holt@sgi.com>
To: "David S. Miller" <davem@davemloft.net>
Cc: Willy Tarreau <w@1wt.eu>
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-sctp@vger.kernel.org
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: "Pekka Savola (ipv6)" <pekkas@netcore.fi>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Vlad Yasevich <vladislav.yasevich@hp.com>
Cc: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp.c | 4 | ||||
| -rw-r--r-- | net/ipv4/udp.c | 4 | ||||
| -rw-r--r-- | net/sctp/protocol.c | 4 |
3 files changed, 9 insertions, 3 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index c88ca260585..0e22467e040 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3252,12 +3252,14 @@ void __init tcp_init(void) /* Set the pressure threshold to be a fraction of global memory that * is up to 1/2 at 256 MB, decreasing toward zero with the amount of - * memory, with a floor of 128 pages. + * memory, with a floor of 128 pages, and a ceiling that prevents an + * integer overflow. */ nr_pages = totalram_pages - totalhigh_pages; limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT); limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11); limit = max(limit, 128UL); + limit = min(limit, INT_MAX * 4UL / 3 / 2); sysctl_tcp_mem[0] = limit / 4 * 3; sysctl_tcp_mem[1] = limit; sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2; diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 434dd677741..f0fbbba1d20 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -2167,12 +2167,14 @@ void __init udp_init(void) udp_table_init(&udp_table, "UDP"); /* Set the pressure threshold up by the same strategy of TCP. It is a * fraction of global memory that is up to 1/2 at 256 MB, decreasing - * toward zero with the amount of memory, with a floor of 128 pages. + * toward zero with the amount of memory, with a floor of 128 pages, + * and a ceiling that prevents an integer overflow. */ nr_pages = totalram_pages - totalhigh_pages; limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT); limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11); limit = max(limit, 128UL); + limit = min(limit, INT_MAX * 4UL / 3 / 2); sysctl_udp_mem[0] = limit / 4 * 3; sysctl_udp_mem[1] = limit; sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2; diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c index 182749867c7..b3d890fdf51 100644 --- a/net/sctp/protocol.c +++ b/net/sctp/protocol.c @@ -1161,7 +1161,8 @@ SCTP_STATIC __init int sctp_init(void) /* Set the pressure threshold to be a fraction of global memory that * is up to 1/2 at 256 MB, decreasing toward zero with the amount of - * memory, with a floor of 128 pages. + * memory, with a floor of 128 pages, and a ceiling that prevents an + * integer overflow. * Note this initalizes the data in sctpv6_prot too * Unabashedly stolen from tcp_init */ @@ -1169,6 +1170,7 @@ SCTP_STATIC __init int sctp_init(void) limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT); limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11); limit = max(limit, 128UL); + limit = min(limit, INT_MAX * 4UL / 3 / 2); sysctl_sctp_mem[0] = limit / 4 * 3; sysctl_sctp_mem[1] = limit; sysctl_sctp_mem[2] = sysctl_sctp_mem[0] * 2; |