commit 6e017006 upstream.

gcc-7 detects that wlanhdr_to_ethhdr() in two drivers calls memcpy() with
a destination argument that an earlier function call may have set to NULL:

staging/rtl8188eu/core/rtw_recv.c: In function 'wlanhdr_to_ethhdr':
staging/rtl8188eu/core/rtw_recv.c:1318:2: warning: argument 1 null where non-null expected [-Wnonnull]
staging/rtl8712/rtl871x_recv.c: In function 'r8712_wlanhdr_to_ethhdr':
staging/rtl8712/rtl871x_recv.c:649:2: warning: argument 1 null where non-null expected [-Wnonnull]

I'm fixing this by adding a NULL pointer check and returning failure
from the function, which is hopefully already handled properly.

This seems to date back to when the drivers were originally added,
so backporting the fix to stable seems appropriate. There are other
related realtek drivers in the kernel, but none of them contain a
function with a similar name or produce this warning.

Fixes: 1cc18a22 ("staging: r8188eu: Add files for new driver - part 5")
Fixes: 2865d42c ("staging: r8712u: Add the new driver to the mainline kernel")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: drop changes to r8188eu]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 39712e8b upstream.

Make sure to detect and return an error on zero-length control-message
transfers when reading from the device.

This addresses a potential failure to detect an empty transmit buffer
during close.

Also remove a redundant check for short transfer when sending a command.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 1eac5c24 upstream.

Make sure to detect short control-message transfers rather than continue
with zero-initialised data when retrieving modem status and during
device initialisation.

Fixes: 52af9545 ("USB: add USB serial ssu100 driver")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 36356a66 upstream.

Make sure to detect short control-message transfers so that errors are
logged when reading the modem status at open.

Note that while this also avoids initialising the modem status using
uninitialised heap data, these bits could not leak to user space as they
are currently not used.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 3c0e25d8 upstream.

Make sure to detect short control-message transfers and log an error
when reading incomplete manufacturer and boot descriptors.

Note that the default all-zero descriptors will now be used after a
short transfer is detected instead of partially initialised ones.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit e4457d97 upstream.

Use a dedicated buffer for the DMA transfer and make sure to detect
short transfers to avoid parsing a corrupt descriptor.

Fixes: 6e8cf775 ("USB: add EPIC support to the io_edgeport driver")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit e3e574ad upstream.

Make sure to detect short responses when reading the latency timer to
avoid using stale buffer data.

Note that no heap data would currently leak through sysfs as
ASYNC_LOW_LATENCY is set by default.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 427c3a95 upstream.

Make sure to detect short responses when fetching the modem status in
order to avoid parsing uninitialised buffer data and having bits of it
leak to user space.

Note that we still allow for short 1-byte responses.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit b631433b upstream.

Fix open error handling which failed to detect errors when reading the
MSR and LSR registers, something which could lead to the shadow
registers being initialised from errnos.

Note that calling the generic close implementation is sufficient in the
error paths as the interrupt urb has not yet been submitted and the
register updates have not been made.

Fixes: f4c1e8d5 ("USB: ark3116: Make existing functions 16450-aware
and add close and release functions.")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 9fef37d7 upstream.

The current implementation failed to detect short transfers, something
which could lead to bits of the uninitialised heap transfer buffer
leaking to user space.

Fixes: 149fc791 ("USB: ark3116: Setup some basic infrastructure for
new ark3116 driver.")
Fixes: f4c1e8d5 ("USB: ark3116: Make existing functions 16450-aware
and add close and release functions.")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit a0467a96 upstream.

The modem-status register was read as part of device configuration at
port_probe and then again at open (and reset-resume). During open (and
reset-resume) the MSR was read before submitting the interrupt URB,
something which could lead to an MSR-change going unnoticed when it
races with open (reset-resume).

Fix this by dropping the redundant reconfiguration of the port at every
open, and only read the MSR after the interrupt URB has been submitted.

Fixes: 664d5df9 ("USB: usb-serial ch341: support for DTR/RTS/CTS")
Signed-off-by: Johan Hovold <johan@kernel.org>
[bwh: Backported to 3.2:
 - Adjust context
 - Keep the 'serial' variable in ch341_open()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 27d41d29 upstream.

Since ipoib_cm_tx_start function and ipoib_cm_tx_reap function
belong to different work queues, they can run in parallel.
In this case if ipoib_cm_tx_reap calls list_del and release the
lock, ipoib_cm_tx_start may acquire it and call list_del_init
on the already deleted object.
Changing list_del to list_del_init in ipoib_cm_tx_reap fixes the problem.

Fixes: 839fcaba ("IPoIB: Connected mode experimental support")
Signed-off-by: Feras Daoud <ferasda@mellanox.com>
Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
Reviewed-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 80b5b35a upstream.

When changing the connection mode, the ipoib_set_mode function
did not check if the previous connection mode equals to the
new one. This commit adds the required check and return 0 if the new
mode equals to the previous one.

Fixes: 839fcaba ("IPoIB: Connected mode experimental support")
Signed-off-by: Feras Daoud <ferasda@mellanox.com>
Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
Reviewed-by: Alex Vesker <valex@mellanox.com>
Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
[bwh: Backported to 3.2:
 - Adjust filename
 - Unlock RTNL lock before returning]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 55efcfcd upstream.

The RDMA core uses ib_pack() to convert from unpacked CPU structs
to on-the-wire bitpacked structs.

This process requires that 1 bit fields are declared as u8 in the
unpacked struct, otherwise the packing process does not read the
value properly and the packed result is wired to 0. Several
places wrongly used int.

Crucially this means the kernel has never, set reversible
correctly in the path record request. It has always asked for
irreversible paths even if the ULP requests otherwise.

When the kernel is used with a SM that supports this feature, it
completely breaks communication management if reversible paths are
not properly requested.

The only reason this ever worked is because opensm ignores the
reversible bit.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit a70e1d6f upstream.

Simply return -EOPNOTSUPP instead.
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit abe81f3b upstream.

If the driver is built as a module, autoload won't work because the module
alias information is not filled. So user-space can't match the registered
device with the corresponding module.

Export the module alias information using the MODULE_DEVICE_TABLE() macro.

Before this patch:

$ modinfo drivers/tty/serial/msm_serial.ko | grep alias
$

After this patch:

$ modinfo drivers/tty/serial/msm_serial.ko | grep alias
alias:          of:N*T*Cqcom,msm-uartdmC*
alias:          of:N*T*Cqcom,msm-uartdm
alias:          of:N*T*Cqcom,msm-uartC*
alias:          of:N*T*Cqcom,msm-uart
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit c705a6b3 upstream.

We accidentally return success when adm8211_alloc_rings() fails but we
should preserve the error code.

Fixes: cc0b88cf ("[PATCH] Add adm8211 802.11b wireless driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

The "dead" key type has no match operation, and a search for keys of
this type can cause a null dereference in keyring_search_aux().
keyring_search() has a check for this, but request_keyring_and_link()
does not.  Move the check into keyring_search_aux(), covering both of
them.

This was fixed upstream by commit c06cfb08 ("KEYS: Remove
key_type::match in favour of overriding default by match_preparse"),
part of a series of large changes that are not suitable for
backporting.

CVE-2017-2647 / CVE-2017-6951
Reported-by: Igor Redko <redkoi@virtuozzo.com>
Reported-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
References: https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-2647Reported-by: idl3r <idler1984@gmail.com>
References: https://www.spinics.net/lists/keyrings/msg01845.htmlSigned-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: David Howells <dhowells@redhat.com>

commit 32c23116 upstream.

Lock socket before checking the SOCK_ZAPPED flag in l2tp_ip6_bind().
Without lock, a concurrent call could modify the socket flags between
the sock_flag(sk, SOCK_ZAPPED) test and the lock_sock() call. This way,
a socket could be inserted twice in l2tp_ip6_bind_table. Releasing it
would then leave a stale pointer there, generating use-after-free
errors when walking through the list or modifying adjacent entries.

BUG: KASAN: use-after-free in l2tp_ip6_close+0x22e/0x290 at addr ffff8800081b0ed8
Write of size 8 by task syz-executor/10987
CPU: 0 PID: 10987 Comm: syz-executor Not tainted 4.8.0+ #39
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.2-0-g33fbe13 by qemu-project.org 04/01/2014
 ffff880031d97838 ffffffff829f835b ffff88001b5a1640 ffff8800081b0ec0
 ffff8800081b15a0 ffff8800081b6d20 ffff880031d97860 ffffffff8174d3cc
 ffff880031d978f0 ffff8800081b0e80 ffff88001b5a1640 ffff880031d978e0
Call Trace:
 [<ffffffff829f835b>] dump_stack+0xb3/0x118 lib/dump_stack.c:15
 [<ffffffff8174d3cc>] kasan_object_err+0x1c/0x70 mm/kasan/report.c:156
 [<     inline     >] print_address_description mm/kasan/report.c:194
 [<ffffffff8174d666>] kasan_report_error+0x1f6/0x4d0 mm/kasan/report.c:283
 [<     inline     >] kasan_report mm/kasan/report.c:303
 [<ffffffff8174db7e>] __asan_report_store8_noabort+0x3e/0x40 mm/kasan/report.c:329
 [<     inline     >] __write_once_size ./include/linux/compiler.h:249
 [<     inline     >] __hlist_del ./include/linux/list.h:622
 [<     inline     >] hlist_del_init ./include/linux/list.h:637
 [<ffffffff8579047e>] l2tp_ip6_close+0x22e/0x290 net/l2tp/l2tp_ip6.c:239
 [<ffffffff850b2dfd>] inet_release+0xed/0x1c0 net/ipv4/af_inet.c:415
 [<ffffffff851dc5a0>] inet6_release+0x50/0x70 net/ipv6/af_inet6.c:422
 [<ffffffff84c4581d>] sock_release+0x8d/0x1d0 net/socket.c:570
 [<ffffffff84c45976>] sock_close+0x16/0x20 net/socket.c:1017
 [<ffffffff817a108c>] __fput+0x28c/0x780 fs/file_table.c:208
 [<ffffffff817a1605>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff813774f9>] task_work_run+0xf9/0x170
 [<ffffffff81324aae>] do_exit+0x85e/0x2a00
 [<ffffffff81326dc8>] do_group_exit+0x108/0x330
 [<ffffffff81348cf7>] get_signal+0x617/0x17a0 kernel/signal.c:2307
 [<ffffffff811b49af>] do_signal+0x7f/0x18f0
 [<ffffffff810039bf>] exit_to_usermode_loop+0xbf/0x150 arch/x86/entry/common.c:156
 [<     inline     >] prepare_exit_to_usermode arch/x86/entry/common.c:190
 [<ffffffff81006060>] syscall_return_slowpath+0x1a0/0x1e0 arch/x86/entry/common.c:259
 [<ffffffff85e4d726>] entry_SYSCALL_64_fastpath+0xc4/0xc6
Object at ffff8800081b0ec0, in cache L2TP/IPv6 size: 1448
Allocated:
PID = 10987
 [ 1116.897025] [<ffffffff811ddcb6>] save_stack_trace+0x16/0x20
 [ 1116.897025] [<ffffffff8174c736>] save_stack+0x46/0xd0
 [ 1116.897025] [<ffffffff8174c9ad>] kasan_kmalloc+0xad/0xe0
 [ 1116.897025] [<ffffffff8174cee2>] kasan_slab_alloc+0x12/0x20
 [ 1116.897025] [<     inline     >] slab_post_alloc_hook mm/slab.h:417
 [ 1116.897025] [<     inline     >] slab_alloc_node mm/slub.c:2708
 [ 1116.897025] [<     inline     >] slab_alloc mm/slub.c:2716
 [ 1116.897025] [<ffffffff817476a8>] kmem_cache_alloc+0xc8/0x2b0 mm/slub.c:2721
 [ 1116.897025] [<ffffffff84c4f6a9>] sk_prot_alloc+0x69/0x2b0 net/core/sock.c:1326
 [ 1116.897025] [<ffffffff84c58ac8>] sk_alloc+0x38/0xae0 net/core/sock.c:1388
 [ 1116.897025] [<ffffffff851ddf67>] inet6_create+0x2d7/0x1000 net/ipv6/af_inet6.c:182
 [ 1116.897025] [<ffffffff84c4af7b>] __sock_create+0x37b/0x640 net/socket.c:1153
 [ 1116.897025] [<     inline     >] sock_create net/socket.c:1193
 [ 1116.897025] [<     inline     >] SYSC_socket net/socket.c:1223
 [ 1116.897025] [<ffffffff84c4b46f>] SyS_socket+0xef/0x1b0 net/socket.c:1203
 [ 1116.897025] [<ffffffff85e4d685>] entry_SYSCALL_64_fastpath+0x23/0xc6
Freed:
PID = 10987
 [ 1116.897025] [<ffffffff811ddcb6>] save_stack_trace+0x16/0x20
 [ 1116.897025] [<ffffffff8174c736>] save_stack+0x46/0xd0
 [ 1116.897025] [<ffffffff8174cf61>] kasan_slab_free+0x71/0xb0
 [ 1116.897025] [<     inline     >] slab_free_hook mm/slub.c:1352
 [ 1116.897025] [<     inline     >] slab_free_freelist_hook mm/slub.c:1374
 [ 1116.897025] [<     inline     >] slab_free mm/slub.c:2951
 [ 1116.897025] [<ffffffff81748b28>] kmem_cache_free+0xc8/0x330 mm/slub.c:2973
 [ 1116.897025] [<     inline     >] sk_prot_free net/core/sock.c:1369
 [ 1116.897025] [<ffffffff84c541eb>] __sk_destruct+0x32b/0x4f0 net/core/sock.c:1444
 [ 1116.897025] [<ffffffff84c5aca4>] sk_destruct+0x44/0x80 net/core/sock.c:1452
 [ 1116.897025] [<ffffffff84c5ad33>] __sk_free+0x53/0x220 net/core/sock.c:1460
 [ 1116.897025] [<ffffffff84c5af23>] sk_free+0x23/0x30 net/core/sock.c:1471
 [ 1116.897025] [<ffffffff84c5cb6c>] sk_common_release+0x28c/0x3e0 ./include/net/sock.h:1589
 [ 1116.897025] [<ffffffff8579044e>] l2tp_ip6_close+0x1fe/0x290 net/l2tp/l2tp_ip6.c:243
 [ 1116.897025] [<ffffffff850b2dfd>] inet_release+0xed/0x1c0 net/ipv4/af_inet.c:415
 [ 1116.897025] [<ffffffff851dc5a0>] inet6_release+0x50/0x70 net/ipv6/af_inet6.c:422
 [ 1116.897025] [<ffffffff84c4581d>] sock_release+0x8d/0x1d0 net/socket.c:570
 [ 1116.897025] [<ffffffff84c45976>] sock_close+0x16/0x20 net/socket.c:1017
 [ 1116.897025] [<ffffffff817a108c>] __fput+0x28c/0x780 fs/file_table.c:208
 [ 1116.897025] [<ffffffff817a1605>] ____fput+0x15/0x20 fs/file_table.c:244
 [ 1116.897025] [<ffffffff813774f9>] task_work_run+0xf9/0x170
 [ 1116.897025] [<ffffffff81324aae>] do_exit+0x85e/0x2a00
 [ 1116.897025] [<ffffffff81326dc8>] do_group_exit+0x108/0x330
 [ 1116.897025] [<ffffffff81348cf7>] get_signal+0x617/0x17a0 kernel/signal.c:2307
 [ 1116.897025] [<ffffffff811b49af>] do_signal+0x7f/0x18f0
 [ 1116.897025] [<ffffffff810039bf>] exit_to_usermode_loop+0xbf/0x150 arch/x86/entry/common.c:156
 [ 1116.897025] [<     inline     >] prepare_exit_to_usermode arch/x86/entry/common.c:190
 [ 1116.897025] [<ffffffff81006060>] syscall_return_slowpath+0x1a0/0x1e0 arch/x86/entry/common.c:259
 [ 1116.897025] [<ffffffff85e4d726>] entry_SYSCALL_64_fastpath+0xc4/0xc6
Memory state around the buggy address:
 ffff8800081b0d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8800081b0e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8800081b0e80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                                    ^
 ffff8800081b0f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8800081b0f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

==================================================================

The same issue exists with l2tp_ip_bind() and l2tp_ip_bind_table.

Fixes: c51ce497 ("l2tp: fix oops in L2TP IP sockets for connect() AF_UNSPEC case")
Reported-by: Baozeng Ding <sploving1@gmail.com>
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Baozeng Ding <sploving1@gmail.com>
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: drop IPv6 changes]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

This is a stable follow up fix for an incorrect backport. The issue is
not present in the upstream kernel.

Miroslav has noticed the following splat when testing my 3.2 forward
port of 8310d48b ("mm/huge_memory.c: respect FOLL_FORCE/FOLL_COW for
thp") to 3.12:

BUG: Bad page state in process a.out  pfn:26400
page:ffffea000085e000 count:0 mapcount:1 mapping:          (null) index:0x7f049d600
page flags: 0x1fffff80108018(uptodate|dirty|head|swapbacked)
page dumped because: nonzero mapcount
[iii]
CPU: 2 PID: 5926 Comm: a.out Tainted: G            E    3.12.61-0-default #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014
 0000000000000000 ffffffff81515830 ffffea000085e000 ffffffff81800ad7
 ffffffff815118a5 ffffea000085e000 0000000000000000 000fffff80000000
 ffffffff81140f18 fff000007c000000 ffffea000085e000 0000000000000009
Call Trace:
 [<ffffffff8100475d>] dump_trace+0x7d/0x2d0
 [<ffffffff81004a44>] show_stack_log_lvl+0x94/0x170
 [<ffffffff81005ce1>] show_stack+0x21/0x50
 [<ffffffff81515830>] dump_stack+0x5d/0x78
 [<ffffffff815118a5>] bad_page.part.67+0xe8/0x102
 [<ffffffff81140f18>] free_pages_prepare+0x198/0x1b0
 [<ffffffff81141275>] __free_pages_ok+0x15/0xd0
 [<ffffffff8116444c>] __access_remote_vm+0x7c/0x1e0
 [<ffffffff81205afb>] mem_rw.isra.13+0x14b/0x1a0
 [<ffffffff811a3b18>] vfs_write+0xb8/0x1e0
 [<ffffffff811a469b>] SyS_pwrite64+0x6b/0xa0
 [<ffffffff81523b49>] system_call_fastpath+0x16/0x1b
 [<00007f049da18573>] 0x7f049da18572

The problem is that the original 3.2 backport didn't return NULL page on
the FOLL_COW page and so the page got reused.
Reported-and-tested-by: Miroslav Beneš <mbenes@suse.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

Upstream commit 34b2cef2
("ipv4: keep skb->dst around in presence of IP options") incorrectly
root caused commit d826eb14 ("ipv4: PKTINFO doesnt need dst
reference") as bug origin.

This patch should fix the issue for 3.2.xx stable kernels, since IPv4
options seem to get more traction these days, after years of oblivion ;)

Fixes: f84af32c ("net: ip_queue_rcv_skb() helper"))
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Anarcheuz Fritz <anarcheuz@gmail.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 82f2341c upstream.

Currently N_HDLC line discipline uses a self-made singly linked list for
data buffers and has n_hdlc.tbuf pointer for buffer retransmitting after
an error.

The commit be10eb75
("tty: n_hdlc add buffer flushing") introduced racy access to n_hdlc.tbuf.
After tx error concurrent flush_tx_queue() and n_hdlc_send_frames() can put
one data buffer to tx_free_buf_list twice. That causes double free in
n_hdlc_release().

Let's use standard kernel linked list and get rid of n_hdlc.tbuf:
in case of tx error put current data buffer after the head of tx_buf_list.
Signed-off-by: Alexander Popov <alex.popov@linux.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 6d7581e6 upstream.

non-rcu variant of list_first_or_null_rcu
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit e9b736d8 upstream.

The class of 4 n_hdls buf locks is the same because a single function
n_hdlc_buf_list_init is used to init all the locks. But since
flush_tx_queue takes n_hdlc->tx_buf_list.spinlock and then calls
n_hdlc_buf_put which takes n_hdlc->tx_free_buf_list.spinlock, lockdep
emits a warning:
=============================================
[ INFO: possible recursive locking detected ]
4.3.0-25.g91e30a7-default #1 Not tainted
---------------------------------------------
a.out/1248 is trying to acquire lock:
 (&(&list->spinlock)->rlock){......}, at: [<ffffffffa01fd020>] n_hdlc_buf_put+0x20/0x60 [n_hdlc]

but task is already holding lock:
 (&(&list->spinlock)->rlock){......}, at: [<ffffffffa01fdc07>] n_hdlc_tty_ioctl+0x127/0x1d0 [n_hdlc]

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&(&list->spinlock)->rlock);
  lock(&(&list->spinlock)->rlock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

2 locks held by a.out/1248:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff814c9eb0>] tty_ldisc_ref_wait+0x20/0x50
 #1:  (&(&list->spinlock)->rlock){......}, at: [<ffffffffa01fdc07>] n_hdlc_tty_ioctl+0x127/0x1d0 [n_hdlc]
...
Call Trace:
...
 [<ffffffff81738fd0>] _raw_spin_lock_irqsave+0x50/0x70
 [<ffffffffa01fd020>] n_hdlc_buf_put+0x20/0x60 [n_hdlc]
 [<ffffffffa01fdc24>] n_hdlc_tty_ioctl+0x144/0x1d0 [n_hdlc]
 [<ffffffff814c25c1>] tty_ioctl+0x3f1/0xe40
...

Fix it by initializing the spin_locks separately. This removes also
reduntand memset of a freshly kzallocated space.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit dfcb9f4f upstream.

commit 2dcab598 ("sctp: avoid BUG_ON on sctp_wait_for_sndbuf")
attempted to avoid a BUG_ON call when the association being used for a
sendmsg() is blocked waiting for more sndbuf and another thread did a
peeloff operation on such asoc, moving it to another socket.

As Ben Hutchings noticed, then in such case it would return without
locking back the socket and would cause two unlocks in a row.

Further analysis also revealed that it could allow a double free if the
application managed to peeloff the asoc that is created during the
sendmsg call, because then sctp_sendmsg() would try to free the asoc
that was created only for that call.

This patch takes another approach. It will deny the peeloff operation
if there is a thread sleeping on the asoc, so this situation doesn't
exist anymore. This avoids the issues described above and also honors
the syscalls that are already being handled (it can be multiple sendmsg
calls).

Joint work with Xin Long.

Fixes: 2dcab598 ("sctp: avoid BUG_ON on sctp_wait_for_sndbuf")
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 2dcab598 upstream.

Alexander Popov reported that an application may trigger a BUG_ON in
sctp_wait_for_sndbuf if the socket tx buffer is full, a thread is
waiting on it to queue more data and meanwhile another thread peels off
the association being used by the first thread.

This patch replaces the BUG_ON call with a proper error handling. It
will return -EPIPE to the original sendmsg call, similarly to what would
have been done if the association wasn't found in the first place.
Acked-by: Alexander Popov <alex.popov@linux.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 95e91b83 upstream.

The issue is described here, with a nice testcase:

    https://bugzilla.kernel.org/show_bug.cgi?id=192931

The problem is that shmat() calls do_mmap_pgoff() with MAP_FIXED, and
the address rounded down to 0.  For the regular mmap case, the
protection mentioned above is that the kernel gets to generate the
address -- arch_get_unmapped_area() will always check for MAP_FIXED and
return that address.  So by the time we do security_mmap_addr(0) things
get funky for shmat().

The testcase itself shows that while a regular user crashes, root will
not have a problem attaching a nil-page.  There are two possible fixes
to this.  The first, and which this patch does, is to simply allow root
to crash as well -- this is also regular mmap behavior, ie when hacking
up the testcase and adding mmap(...  |MAP_FIXED).  While this approach
is the safer option, the second alternative is to ignore SHM_RND if the
rounded address is 0, thus only having MAP_SHARED flags.  This makes the
behavior of shmat() identical to the mmap() case.  The downside of this
is obviously user visible, but does make sense in that it maintains
semantics after the round-down wrt 0 address and mmap.

Passes shm related ltp tests.

Link: http://lkml.kernel.org/r/1486050195-18629-1-git-send-email-dave@stgolabs.netSigned-off-by: Davidlohr Bueso <dbueso@suse.de>
Reported-by: Gareth Evans <gareth.evans@contextis.co.uk>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: use SHMLBA constant instead of shmlba parameter]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

This reverts commit bc48f6f5, which was
commit 9dbe6cf9 upstream.  It depends on
several other large commits to work, and without them causes a regression.

References: https://bugzilla.redhat.com/show_bug.cgi?id=1408333Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Eric Wheeler <kvm@lists.ewheeler.net>

commit 9c8bb163 upstream.

In function igmpv3/mld_add_delrec() we allocate pmc and put it in
idev->mc_tomb, so we should free it when we don't need it in del_delrec().
But I removed kfree(pmc) incorrectly in latest two patches. Now fix it.

Fixes: 24803f38 ("igmp: do not remove igmp souce list info when ...")
Fixes: 1666d49e ("mld: do not remove mld souce list info when ...")
Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 1666d49e upstream.

This is an IPv6 version of commit 24803f38 ("igmp: do not remove igmp
souce list..."). In mld_del_delrec(), we will restore back all source filter
info instead of flush them.

Move mld_clear_delrec() from ipv6_mc_down() to ipv6_mc_destroy_dev() since
we should not remove source list info when set link down. Remove
igmp6_group_dropped() in ipv6_mc_destroy_dev() since we have called it in
ipv6_mc_down().

Also clear all source info after igmp6_group_dropped() instead of in it
because ipv6_mc_down() will call igmp6_group_dropped().
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2:
 - Timer code moved around in ipv6_mc_down() is different
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 24803f38 upstream.

In commit 24cf3af3 ("igmp: call ip_mc_clear_src..."), we forgot to remove
igmpv3_clear_delrec() in ip_mc_down(), which also called ip_mc_clear_src().
This make us clear all IGMPv3 source filter info after NETDEV_DOWN.
Move igmpv3_clear_delrec() to ip_mc_destroy_dev() and then no need
ip_mc_clear_src() in ip_mc_destroy_dev().

On the other hand, we should restore back instead of free all source filter
info in igmpv3_del_delrec(). Or we will not able to restore IGMPv3 source
filter info after NETDEV_UP and NETDEV_POST_TYPE_CHANGE.

Fixes: 24cf3af3 ("igmp: call ip_mc_clear_src() only when ...")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2:
 - Use IGMP_Unsolicited_Report_Count instead of sysctl_igmp_qrv
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

[ Upstream commit 837585a5 ]

When IFF_VNET_HDR is enabled, a virtio_net header must precede data.
Data length is verified to be greater than or equal to expected header
length tun->vnet_hdr_sz before copying.

Macvtap functions read the value once, but unless READ_ONCE is used,
the compiler may ignore this and read multiple times. Enforce a single
read and locally cached value to avoid updates between test and use.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Suggested-by: Eric Dumazet <edumazet@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: BAckported to 3.2:
 - Use ACCESS_ONCE() instead of READ_ONCE()
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

[ Upstream commit e1edab87 ]

When IFF_VNET_HDR is enabled, a virtio_net header must precede data.
Data length is verified to be greater than or equal to expected header
length tun->vnet_hdr_sz before copying.

Read this value once and cache locally, as it can be updated between
the test and use (TOCTOU).
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
CC: Eric Dumazet <edumazet@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2:
 - Use ACCESS_ONCE() instead of READ_ONCE()
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 2eb783c4 upstream.

We set the flag TUN_PKT_STRIP if the user buffer provided is too
small to contain the entire packet plus meta-data.  However, this
has been broken ever since we added GSO meta-data.  VLAN acceleration
also has the same problem.

This patch fixes this by taking both into account when setting the
TUN_PKT_STRIP flag.

The fact that this has been broken for six years without anyone
realising means that nobody actually uses this flag.

Fixes: f43798c2 ("tun: Allow GSO using virtio_net_hdr")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2:
 - No VLAN acceleration support
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

[ Upstream commit 06425c30 ]

syszkaller fuzzer was able to trigger a divide by zero, when
TCP window scaling is not enabled.

SO_RCVBUF can be used not only to increase sk_rcvbuf, also
to decrease it below current receive buffers utilization.

If mss is negative or 0, just return a zero TCP window.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov  <dvyukov@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

[ Upstream commit 63117f09 ]

Casting is a high precedence operation but "off" and "i" are in terms of
bytes so we need to have some parenthesis here.

Fixes: fbfa743a ("ipv6: fix ip6_tnl_parse_tlv_enc_lim()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

[ Upstream commit fbfa743a ]

This function suffers from multiple issues.

First one is that pskb_may_pull() may reallocate skb->head,
so the 'raw' pointer needs either to be reloaded or not used at all.

Second issue is that NEXTHDR_DEST handling does not validate
that the options are present in skb->data, so we might read
garbage or access non existent memory.

With help from Willem de Bruijn.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov  <dvyukov@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

[ Upstream commit f1712c73 ]

Zhang Yanmin reported crashes [1] and provided a patch adding a
synchronize_rcu() call in can_rx_unregister()

The main problem seems that the sockets themselves are not RCU
protected.

If CAN uses RCU for delivery, then sockets should be freed only after
one RCU grace period.

Recent kernels could use sock_set_flag(sk, SOCK_RCU_FREE), but let's
ease stable backports with the following fix instead.

[1]
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff81495e25>] selinux_socket_sock_rcv_skb+0x65/0x2a0

Call Trace:
 <IRQ>
 [<ffffffff81485d8c>] security_sock_rcv_skb+0x4c/0x60
 [<ffffffff81d55771>] sk_filter+0x41/0x210
 [<ffffffff81d12913>] sock_queue_rcv_skb+0x53/0x3a0
 [<ffffffff81f0a2b3>] raw_rcv+0x2a3/0x3c0
 [<ffffffff81f06eab>] can_rcv_filter+0x12b/0x370
 [<ffffffff81f07af9>] can_receive+0xd9/0x120
 [<ffffffff81f07beb>] can_rcv+0xab/0x100
 [<ffffffff81d362ac>] __netif_receive_skb_core+0xd8c/0x11f0
 [<ffffffff81d36734>] __netif_receive_skb+0x24/0xb0
 [<ffffffff81d37f67>] process_backlog+0x127/0x280
 [<ffffffff81d36f7b>] net_rx_action+0x33b/0x4f0
 [<ffffffff810c88d4>] __do_softirq+0x184/0x440
 [<ffffffff81f9e86c>] do_softirq_own_stack+0x1c/0x30
 <EOI>
 [<ffffffff810c76fb>] do_softirq.part.18+0x3b/0x40
 [<ffffffff810c8bed>] do_softirq+0x1d/0x20
 [<ffffffff81d30085>] netif_rx_ni+0xe5/0x110
 [<ffffffff8199cc87>] slcan_receive_buf+0x507/0x520
 [<ffffffff8167ef7c>] flush_to_ldisc+0x21c/0x230
 [<ffffffff810e3baf>] process_one_work+0x24f/0x670
 [<ffffffff810e44ed>] worker_thread+0x9d/0x6f0
 [<ffffffff810e4450>] ? rescuer_thread+0x480/0x480
 [<ffffffff810ebafc>] kthread+0x12c/0x150
 [<ffffffff81f9ccef>] ret_from_fork+0x3f/0x70
Reported-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>