user/sven/linux.git/include, branch v4.1.42

mm: larger stack guard gap, between vmas

2017-06-28T22:57:15Z

[ Upstream commit 1be7107fbe18eed3e319a6c3e83c78254b693acb ] Stack guard page is a useful feature to reduce a risk of stack smashing into a different mapping. We have been using a single page gap which is sufficient to prevent having stack adjacent to a different mapping. But this seems to be insufficient in the light of the stack usage in userspace. E.g. glibc uses as large as 64kB alloca() in many commonly used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX] which is 256kB or stack strings with MAX_ARG_STRLEN. This will become especially dangerous for suid binaries and the default no limit for the stack size limit because those applications can be tricked to consume a large portion of the stack and a single glibc call could jump over the guard page. These attacks are not theoretical, unfortunatelly. Make those attacks less probable by increasing the stack guard gap to 1MB (on systems with 4k pages; but make it depend on the page size because systems with larger base pages might cap stack allocations in the PAGE_SIZE units) which should cover larger alloca() and VLA stack allocations. It is obviously not a full fix because the problem is somehow inherent, but it should reduce attack space a lot. One could argue that the gap size should be configurable from userspace, but that can be done later when somebody finds that the new 1MB is wrong for some special case applications. For now, add a kernel command line option (stack_guard_gap) to specify the stack gap size (in page units). Implementation wise, first delete all the old code for stack guard page: because although we could get away with accounting one extra page in a stack vma, accounting a larger gap can break userspace - case in point, a program run with "ulimit -S -v 20000" failed when the 1MB gap was counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK and strict non-overcommit mode. Instead of keeping gap inside the stack vma, maintain the stack guard gap as a gap between vmas: using vm_start_gap() in place of vm_start (or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few places which need to respect the gap - mainly arch_get_unmapped_area(), and and the vma tree's subtree_gap support for that. Original-patch-by: Oleg Nesterov Original-patch-by: Michal Hocko Signed-off-by: Hugh Dickins Acked-by: Michal Hocko Tested-by: Helge Deller # parisc Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

USB: hub: fix SS max number of ports

2017-06-26T02:02:22Z

[ Upstream commit 93491ced3c87c94b12220dbac0527e1356702179 ] Add define for the maximum number of ports on a SuperSpeed hub as per USB 3.1 spec Table 10-5, and use it when verifying the retrieved hub descriptor. This specifically avoids benign attempts to update the DeviceRemovable mask for non-existing ports (should we get that far). Fixes: dbe79bbe9dcb ("USB 3.0 Hub Changes") Acked-by: Alan Stern Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

log2: make order_base_2() behave correctly on const input value zero

2017-06-26T02:02:20Z

[ Upstream commit 29905b52fad0854351f57bab867647e4982285bf ] The function order_base_2() is defined (according to the comment block) as returning zero on input zero, but subsequently passes the input into roundup_pow_of_two(), which is explicitly undefined for input zero. This has gone unnoticed until now, but optimization passes in GCC 7 may produce constant folded function instances where a constant value of zero is passed into order_base_2(), resulting in link errors against the deliberately undefined '____ilog2_NaN'. So update order_base_2() to adhere to its own documented interface. [ See http://marc.info/?l=linux-kernel&m=147672952517795&w=2 and follow-up discussion for more background. The gcc "optimization pass" is really just broken, but now the GCC trunk problem seems to have escaped out of just specially built daily images, so we need to work around it in mainline. - Linus ] Signed-off-by: Ard Biesheuvel Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

PCI/PM: Add needs_resume flag to avoid suspend complete optimization

2017-06-26T02:02:20Z

[ Upstream commit 4d071c3238987325b9e50e33051a40d1cce311cc ] Some drivers - like i915 - may not support the system suspend direct complete optimization due to differences in their runtime and system suspend sequence. Add a flag that when set resumes the device before calling the driver's system suspend handlers which effectively disables the optimization. Needed by a future patch fixing suspend/resume on i915. Suggested by Rafael. Signed-off-by: Imre Deak Signed-off-by: Bjorn Helgaas Acked-by: Rafael J. Wysocki Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin

cpuset: consider dying css as offline

2017-06-26T02:02:19Z

[ Upstream commit 41c25707d21716826e3c1f60967f5550610ec1c9 ] In most cases, a cgroup controller don't care about the liftimes of cgroups. For the controller, a css becomes online when ->css_online() is called on it and offline when ->css_offline() is called. However, cpuset is special in that the user interface it exposes cares whether certain cgroups exist or not. Combined with the RCU delay between cgroup removal and css offlining, this can lead to user visible behavior oddities where operations which should succeed after cgroup removals fail for some time period. The effects of cgroup removals are delayed when seen from userland. This patch adds css_is_dying() which tests whether offline is pending and updates is_cpuset_online() so that the function returns false also while offline is pending. This gets rid of the userland visible delays. Signed-off-by: Tejun Heo Reported-by: Daniel Jordan Link: http://lkml.kernel.org/r/327ca1f5-7957-fbb9-9e5f-9ba149d40ba2@oracle.com Cc: stable@vger.kernel.org Signed-off-by: Tejun Heo Signed-off-by: Sasha Levin

ptrace: Properly initialize ptracer_cred on fork

2017-06-26T02:02:18Z

[ Upstream commit c70d9d809fdeecedb96972457ee45c49a232d97f ] When I introduced ptracer_cred I failed to consider the weirdness of fork where the task_struct copies the old value by default. This winds up leaving ptracer_cred set even when a process forks and the child process does not wind up being ptraced. Because ptracer_cred is not set on non-ptraced processes whose parents were ptraced this has broken the ability of the enlightenment window manager to start setuid children. Fix this by properly initializing ptracer_cred in ptrace_init_task This must be done with a little bit of care to preserve the current value of ptracer_cred when ptrace carries through fork. Re-reading the ptracer_cred from the ptracing process at this point is inconsistent with how PT_PTRACE_CAP has been maintained all of these years. Tested-by: Takashi Iwai Fixes: 64b875f7ac8a ("ptrace: Capture the ptracer's creds not PT_PTRACE_CAP") Signed-off-by: "Eric W. Biederman" Signed-off-by: Sasha Levin

net: ping: do not abuse udp_poll()

2017-06-25T04:25:36Z

[ Upstream commit 77d4b1d36926a9b8387c6b53eeba42bcaaffcea3 ] Alexander reported various KASAN messages triggered in recent kernels The problem is that ping sockets should not use udp_poll() in the first place, and recent changes in UDP stack finally exposed this old bug. Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind") Fixes: 6d0bfe226116 ("net: ipv6: Add IPv6 support to the ping socket.") Signed-off-by: Eric Dumazet Reported-by: Sasha Levin Cc: Solar Designer Cc: Vasiliy Kulikov Cc: Lorenzo Colitti Acked-By: Lorenzo Colitti Tested-By: Lorenzo Colitti Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

vlan: Fix tcp checksum offloads in Q-in-Q vlans

2017-06-25T04:25:35Z

[ Upstream commit 35d2f80b07bbe03fb358afb0bdeff7437a7d67ff ] It appears that TCP checksum offloading has been broken for Q-in-Q vlans. The behavior was execerbated by the series commit afb0bc972b52 ("Merge branch 'stacked_vlan_tso'") that that enabled accleleration features on stacked vlans. However, event without that series, it is possible to trigger this issue. It just requires a lot more specialized configuration. The root cause is the interaction between how netdev_intersect_features() works, the features actually set on the vlan devices and HW having the ability to run checksum with longer headers. The issue starts when netdev_interesect_features() replaces NETIF_F_HW_CSUM with a combination of NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM, if the HW advertises IP|IPV6 specific checksums. This happens for tagged and multi-tagged packets. However, HW that enables IP|IPV6 checksum offloading doesn't gurantee that packets with arbitrarily long headers can be checksummed. This patch disables IP|IPV6 checksums on the packet for multi-tagged packets. CC: Toshiaki Makita CC: Michal Kubecek Signed-off-by: Vladislav Yasevich Acked-by: Toshiaki Makita Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

f2fs: sanity check segment count

2017-06-13T13:29:21Z

[ Upstream commit b9dd46188edc2f0d1f37328637860bb65a771124 ] F2FS uses 4 bytes to represent block address. As a result, supported size of disk is 16 TB and it equals to 16 * 1024 * 1024 / 2 segments. Signed-off-by: Jin Qian Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin

ipv6: reorder ip6_route_dev_notifier after ipv6_dev_notf

2017-06-13T13:29:21Z

[ Upstream commit 242d3a49a2a1a71d8eb9f953db1bcaa9d698ce00 ] For each netns (except init_net), we initialize its null entry in 3 places: 1) The template itself, as we use kmemdup() 2) Code around dst_init_metrics() in ip6_route_net_init() 3) ip6_route_dev_notify(), which is supposed to initialize it after loopback registers Unfortunately the last one still happens in a wrong order because we expect to initialize net->ipv6.ip6_null_entry->rt6i_idev to net->loopback_dev's idev, thus we have to do that after we add idev to loopback. However, this notifier has priority == 0 same as ipv6_dev_notf, and ipv6_dev_notf is registered after ip6_route_dev_notifier so it is called actually after ip6_route_dev_notifier. This is similar to commit 2f460933f58e ("ipv6: initialize route null entry in addrconf_init()") which fixes init_net. Fix it by picking a smaller priority for ip6_route_dev_notifier. Also, we have to release the refcnt accordingly when unregistering loopback_dev because device exit functions are called before subsys exit functions. Acked-by: David Ahern Tested-by: David Ahern Signed-off-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Sasha Levin