2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Robin Holt <holt@xxxxxxx> [ Problem was fixed differently upstream. -DaveM ] 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@xxxxxxx> To: "David S. Miller" <davem@xxxxxxxxxxxxx> Cc: Willy Tarreau <w@xxxxxx> Cc: linux-kernel@xxxxxxxxxxxxxxx Cc: netdev@xxxxxxxxxxxxxxx Cc: linux-sctp@xxxxxxxxxxxxxxx Cc: Alexey Kuznetsov <kuznet@xxxxxxxxxxxxx> Cc: "Pekka Savola (ipv6)" <pekkas@xxxxxxxxxx> Cc: James Morris <jmorris@xxxxxxxxx> Cc: Hideaki YOSHIFUJI <yoshfuji@xxxxxxxxxxxxxx> Cc: Patrick McHardy <kaber@xxxxxxxxx> Cc: Vlad Yasevich <vladislav.yasevich@xxxxxx> Cc: Sridhar Samudrala <sri@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx> --- net/ipv4/tcp.c | 4 +++- net/ipv4/udp.c | 4 +++- net/sctp/protocol.c | 4 +++- 3 files changed, 9 insertions(+), 3 deletions(-) --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2754,12 +2754,14 @@ 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; --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1722,11 +1722,13 @@ void __init udp_init(void) /* 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. */ limit = min(nr_all_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT); limit = (limit * (nr_all_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; --- a/net/sctp/protocol.c +++ b/net/sctp/protocol.c @@ -1179,7 +1179,8 @@ 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 */ @@ -1187,6 +1188,7 @@ 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; -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
