linux-stable.git/include, branch v5.4.44 Linux kernel stable tree netfilter: nf_conntrack_pptp: fix compilation warning with W=1 build 2020-06-03T06:21:39+00:00 Pablo Neira Ayuso pablo@netfilter.org 2020-05-27T10:24:10+00:00 3f57fa847e276a0f0f9d72e4707f35b9362f815a commit 4946ea5c1237036155c3b3a24f049fd5f849f8f6 upstream. >> include/linux/netfilter/nf_conntrack_pptp.h:13:20: warning: 'const' type qualifier on return type has no effect [-Wignored-qualifiers] extern const char *const pptp_msg_name(u_int16_t msg); ^~~~~~ Reported-by: kbuild test robot <lkp@intel.com> Fixes: 4c559f15efcc ("netfilter: nf_conntrack_pptp: prevent buffer overflows in debug code") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4946ea5c1237036155c3b3a24f049fd5f849f8f6 upstream.

>> include/linux/netfilter/nf_conntrack_pptp.h:13:20: warning: 'const' type qualifier on return type has no effect [-Wignored-qualifiers]
extern const char *const pptp_msg_name(u_int16_t msg);
^~~~~~

Reported-by: kbuild test robot <lkp@intel.com>
Fixes: 4c559f15efcc ("netfilter: nf_conntrack_pptp: prevent buffer overflows in debug code")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv4: nexthop version of fib_info_nh_uses_dev 2020-06-03T06:21:37+00:00 David Ahern dsahern@gmail.com 2020-05-26T18:56:18+00:00 35c0a6e7ef5524bd58a66d42d5859ec3ce1baf48 commit 1fd1c768f3624a5e66766e7b4ddb9b607cd834a5 upstream. Similar to the last path, need to fix fib_info_nh_uses_dev for external nexthops to avoid referencing multiple nh_grp structs. Move the device check in fib_info_nh_uses_dev to a helper and create a nexthop version that is called if the fib_info uses an external nexthop. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 1fd1c768f3624a5e66766e7b4ddb9b607cd834a5 upstream.

Similar to the last path, need to fix fib_info_nh_uses_dev for
external nexthops to avoid referencing multiple nh_grp structs.
Move the device check in fib_info_nh_uses_dev to a helper and
create a nexthop version that is called if the fib_info uses an
external nexthop.

Fixes: 430a049190de ("nexthop: Add support for nexthop groups")
Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
nexthop: Expand nexthop_is_multipath in a few places 2020-06-03T06:21:37+00:00 David Ahern dsahern@gmail.com 2020-05-26T18:56:16+00:00 568c159356d1ae93f5273dc511d0fa375305f0e7 commit 0b5e2e39739e861fa5fc84ab27a35dbe62a15330 upstream. I got too fancy consolidating checks on multipath type. The result is that path lookups can access 2 different nh_grp structs as exposed by Nik's torture tests. Expand nexthop_is_multipath within nexthop.h to avoid multiple, nh_grp dereferences and make decisions based on the consistent struct. Only 2 places left using nexthop_is_multipath are within IPv6, both only check that the nexthop is a multipath for a branching decision which are acceptable. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 0b5e2e39739e861fa5fc84ab27a35dbe62a15330 upstream.

I got too fancy consolidating checks on multipath type. The result
is that path lookups can access 2 different nh_grp structs as exposed
by Nik's torture tests. Expand nexthop_is_multipath within nexthop.h to
avoid multiple, nh_grp dereferences and make decisions based on the
consistent struct.

Only 2 places left using nexthop_is_multipath are within IPv6, both
only check that the nexthop is a multipath for a branching decision
which are acceptable.

Fixes: 430a049190de ("nexthop: Add support for nexthop groups")
Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
nexthops: don't modify published nexthop groups 2020-06-03T06:21:37+00:00 Nikolay Aleksandrov nikolay@cumulusnetworks.com 2020-05-26T18:56:15+00:00 88e81db5509b32a1fb3b1efc82757cd8990ea484 commit 90f33bffa382598a32cc82abfeb20adc92d041b6 upstream. We must avoid modifying published nexthop groups while they might be in use, otherwise we might see NULL ptr dereferences. In order to do that we allocate 2 nexthoup group structures upon nexthop creation and swap between them when we have to delete an entry. The reason is that we can't fail nexthop group removal, so we can't handle allocation failure thus we move the extra allocation on creation where we can safely fail and return ENOMEM. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 90f33bffa382598a32cc82abfeb20adc92d041b6 upstream.

We must avoid modifying published nexthop groups while they might be
in use, otherwise we might see NULL ptr dereferences. In order to do
that we allocate 2 nexthoup group structures upon nexthop creation
and swap between them when we have to delete an entry. The reason is
that we can't fail nexthop group removal, so we can't handle allocation
failure thus we move the extra allocation on creation where we can
safely fail and return ENOMEM.

Fixes: 430a049190de ("nexthop: Add support for nexthop groups")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ieee80211: Fix incorrect mask for default PE duration 2020-06-03T06:21:36+00:00 Pradeep Kumar Chitrapu pradeepc@codeaurora.org 2020-05-06T10:24:30+00:00 73c05545fbb558f40ffc2bc81bcd011a340472cd commit d031781bdabe1027858a3220f868866586bf6e7c upstream. Fixes bitmask for HE opration's default PE duration. Fixes: daa5b83513a7 ("mac80211: update HE operation fields to D3.0") Signed-off-by: Pradeep Kumar Chitrapu <pradeepc@codeaurora.org> Link: https://lore.kernel.org/r/20200506102430.5153-1-pradeepc@codeaurora.org Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d031781bdabe1027858a3220f868866586bf6e7c upstream.

Fixes bitmask for HE opration's default PE duration.

Fixes: daa5b83513a7 ("mac80211: update HE operation fields to D3.0")
Signed-off-by: Pradeep Kumar Chitrapu <pradeepc@codeaurora.org>
Link: https://lore.kernel.org/r/20200506102430.5153-1-pradeepc@codeaurora.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netfilter: nf_conntrack_pptp: prevent buffer overflows in debug code 2020-06-03T06:21:35+00:00 Pablo Neira Ayuso pablo@netfilter.org 2020-05-14T12:14:23+00:00 9f57771d09f4e62724144f49e3d40b9485f4ab4f commit 4c559f15efcc43b996f4da528cd7f9483aaca36d upstream. Dan Carpenter says: "Smatch complains that the value for "cmd" comes from the network and can't be trusted." Add pptp_msg_name() helper function that checks for the array boundary. Fixes: f09943fefe6b ("[NETFILTER]: nf_conntrack/nf_nat: add PPTP helper port") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4c559f15efcc43b996f4da528cd7f9483aaca36d upstream.

Dan Carpenter says: "Smatch complains that the value for "cmd" comes
from the network and can't be trusted."

Add pptp_msg_name() helper function that checks for the array boundary.

Fixes: f09943fefe6b ("[NETFILTER]: nf_conntrack/nf_nat: add PPTP helper port")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xfrm: fix error in comment 2020-06-03T06:21:33+00:00 Antony Antony antony@phenome.org 2020-04-15T19:47:10+00:00 0de9bed087a2f2da16f8550ec6b673b50730a948 commit 29e4276667e24ee6b91d9f91064d8fda9a210ea1 upstream. s/xfrm_state_offload/xfrm_user_offload/ Fixes: d77e38e612a ("xfrm: Add an IPsec hardware offloading API") Signed-off-by: Antony Antony <antony@phenome.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 29e4276667e24ee6b91d9f91064d8fda9a210ea1 upstream.

s/xfrm_state_offload/xfrm_user_offload/

Fixes: d77e38e612a ("xfrm: Add an IPsec hardware offloading API")
Signed-off-by: Antony Antony <antony@phenome.org>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
include/asm-generic/topology.h: guard cpumask_of_node() macro argument 2020-06-03T06:21:27+00:00 Arnd Bergmann arnd@arndb.de 2020-05-28T05:20:55+00:00 31f0b78bb4781a75f73aa462e4731a9b0eb102a6 [ Upstream commit 4377748c7b5187c3342a60fa2ceb60c8a57a8488 ] drivers/hwmon/amd_energy.c:195:15: error: invalid operands to binary expression ('void' and 'int') (channel - data->nr_cpus)); ~~~~~~~~~^~~~~~~~~~~~~~~~~ include/asm-generic/topology.h:51:42: note: expanded from macro 'cpumask_of_node' #define cpumask_of_node(node) ((void)node, cpu_online_mask) ^~~~ include/linux/cpumask.h:618:72: note: expanded from macro 'cpumask_first_and' #define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p)) ^~~~~ Fixes: f0b848ce6fe9 ("cpumask: Introduce cpumask_of_{node,pcibus} to replace {node,pcibus}_to_cpumask") Fixes: 8abee9566b7e ("hwmon: Add amd_energy driver to report energy counters") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Guenter Roeck <linux@roeck-us.net> Link: http://lkml.kernel.org/r/20200527134623.930247-1-arnd@arndb.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 4377748c7b5187c3342a60fa2ceb60c8a57a8488 ]

drivers/hwmon/amd_energy.c:195:15: error: invalid operands to binary expression ('void' and 'int')
                                        (channel - data->nr_cpus));
                                        ~~~~~~~~~^~~~~~~~~~~~~~~~~
include/asm-generic/topology.h:51:42: note: expanded from macro 'cpumask_of_node'
    #define cpumask_of_node(node)       ((void)node, cpu_online_mask)
                                               ^~~~
include/linux/cpumask.h:618:72: note: expanded from macro 'cpumask_first_and'
 #define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p))
                                                                       ^~~~~

Fixes: f0b848ce6fe9 ("cpumask: Introduce cpumask_of_{node,pcibus} to replace {node,pcibus}_to_cpumask")
Fixes: 8abee9566b7e ("hwmon: Add amd_energy driver to report energy counters")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Link: http://lkml.kernel.org/r/20200527134623.930247-1-arnd@arndb.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
mm: remove VM_BUG_ON(PageSlab()) from page_mapcount() 2020-06-03T06:21:26+00:00 Konstantin Khlebnikov khlebnikov@yandex-team.ru 2020-05-28T05:20:47+00:00 de482c445b0fa127901f497b4d68f0c9fbf449d5 [ Upstream commit 6988f31d558aa8c744464a7f6d91d34ada48ad12 ] Replace superfluous VM_BUG_ON() with comment about correct usage. Technically reverts commit 1d148e218a0d ("mm: add VM_BUG_ON_PAGE() to page_mapcount()"), but context lines have changed. Function isolate_migratepages_block() runs some checks out of lru_lock when choose pages for migration. After checking PageLRU() it checks extra page references by comparing page_count() and page_mapcount(). Between these two checks page could be removed from lru, freed and taken by slab. As a result this race triggers VM_BUG_ON(PageSlab()) in page_mapcount(). Race window is tiny. For certain workload this happens around once a year. page:ffffea0105ca9380 count:1 mapcount:0 mapping:ffff88ff7712c180 index:0x0 compound_mapcount: 0 flags: 0x500000000008100(slab|head) raw: 0500000000008100 dead000000000100 dead000000000200 ffff88ff7712c180 raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000 page dumped because: VM_BUG_ON_PAGE(PageSlab(page)) ------------[ cut here ]------------ kernel BUG at ./include/linux/mm.h:628! invalid opcode: 0000 [#1] SMP NOPTI CPU: 77 PID: 504 Comm: kcompactd1 Tainted: G W 4.19.109-27 #1 Hardware name: Yandex T175-N41-Y3N/MY81-EX0-Y3N, BIOS R05 06/20/2019 RIP: 0010:isolate_migratepages_block+0x986/0x9b0 The code in isolate_migratepages_block() was added in commit 119d6d59dcc0 ("mm, compaction: avoid isolating pinned pages") before adding VM_BUG_ON into page_mapcount(). This race has been predicted in 2015 by Vlastimil Babka (see link below). [akpm@linux-foundation.org: comment tweaks, per Hugh] Fixes: 1d148e218a0d ("mm: add VM_BUG_ON_PAGE() to page_mapcount()") Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/159032779896.957378.7852761411265662220.stgit@buzz Link: https://lore.kernel.org/lkml/557710E1.6060103@suse.cz/ Link: https://lore.kernel.org/linux-mm/158937872515.474360.5066096871639561424.stgit@buzz/T/ (v1) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 6988f31d558aa8c744464a7f6d91d34ada48ad12 ]

Replace superfluous VM_BUG_ON() with comment about correct usage.

Technically reverts commit 1d148e218a0d ("mm: add VM_BUG_ON_PAGE() to
page_mapcount()"), but context lines have changed.

Function isolate_migratepages_block() runs some checks out of lru_lock
when choose pages for migration.  After checking PageLRU() it checks
extra page references by comparing page_count() and page_mapcount().
Between these two checks page could be removed from lru, freed and taken
by slab.

As a result this race triggers VM_BUG_ON(PageSlab()) in page_mapcount().
Race window is tiny.  For certain workload this happens around once a
year.

    page:ffffea0105ca9380 count:1 mapcount:0 mapping:ffff88ff7712c180 index:0x0 compound_mapcount: 0
    flags: 0x500000000008100(slab|head)
    raw: 0500000000008100 dead000000000100 dead000000000200 ffff88ff7712c180
    raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000
    page dumped because: VM_BUG_ON_PAGE(PageSlab(page))
    ------------[ cut here ]------------
    kernel BUG at ./include/linux/mm.h:628!
    invalid opcode: 0000 [#1] SMP NOPTI
    CPU: 77 PID: 504 Comm: kcompactd1 Tainted: G        W         4.19.109-27 #1
    Hardware name: Yandex T175-N41-Y3N/MY81-EX0-Y3N, BIOS R05 06/20/2019
    RIP: 0010:isolate_migratepages_block+0x986/0x9b0

The code in isolate_migratepages_block() was added in commit
119d6d59dcc0 ("mm, compaction: avoid isolating pinned pages") before
adding VM_BUG_ON into page_mapcount().

This race has been predicted in 2015 by Vlastimil Babka (see link
below).

[akpm@linux-foundation.org: comment tweaks, per Hugh]
Fixes: 1d148e218a0d ("mm: add VM_BUG_ON_PAGE() to page_mapcount()")
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/159032779896.957378.7852761411265662220.stgit@buzz
Link: https://lore.kernel.org/lkml/557710E1.6060103@suse.cz/
Link: https://lore.kernel.org/linux-mm/158937872515.474360.5066096871639561424.stgit@buzz/T/ (v1)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
RDMA/core: Fix double destruction of uobject 2020-06-03T06:21:25+00:00 Jason Gunthorpe jgg@mellanox.com 2020-05-27T13:55:34+00:00 b5d326a77b7317c731c441fb78292270b98701c9 [ Upstream commit c85f4abe66bea0b5db8d28d55da760c4fe0a0301 ] Fix use after free when user user space request uobject concurrently for the same object, within the RCU grace period. In that case, remove_handle_idr_uobject() is called twice and we will have an extra put on the uobject which cause use after free. Fix it by leaving the uobject write locked after it was removed from the idr. Call to rdma_lookup_put_uobject with UVERBS_LOOKUP_DESTROY instead of UVERBS_LOOKUP_WRITE will do the work. refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 1381 at lib/refcount.c:28 refcount_warn_saturate+0xfe/0x1a0 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 1381 Comm: syz-executor.0 Not tainted 5.5.0-rc3 #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack+0x94/0xce panic+0x234/0x56f __warn+0x1cc/0x1e1 report_bug+0x200/0x310 fixup_bug.part.11+0x32/0x80 do_error_trap+0xd3/0x100 do_invalid_op+0x31/0x40 invalid_op+0x1e/0x30 RIP: 0010:refcount_warn_saturate+0xfe/0x1a0 Code: 0f 0b eb 9b e8 23 f6 6d ff 80 3d 6c d4 19 03 00 75 8d e8 15 f6 6d ff 48 c7 c7 c0 02 55 bd c6 05 57 d4 19 03 01 e8 a2 58 49 ff <0f> 0b e9 6e ff ff ff e8 f6 f5 6d ff 80 3d 42 d4 19 03 00 0f 85 5c RSP: 0018:ffffc90002df7b98 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff88810f6a193c RCX: ffffffffba649009 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88811b0283cc RBP: 0000000000000003 R08: ffffed10236060e3 R09: ffffed10236060e3 R10: 0000000000000001 R11: ffffed10236060e2 R12: ffff88810f6a193c R13: ffffc90002df7d60 R14: 0000000000000000 R15: ffff888116ae6a08 uverbs_uobject_put+0xfd/0x140 __uobj_perform_destroy+0x3d/0x60 ib_uverbs_close_xrcd+0x148/0x170 ib_uverbs_write+0xaa5/0xdf0 __vfs_write+0x7c/0x100 vfs_write+0x168/0x4a0 ksys_write+0xc8/0x200 do_syscall_64+0x9c/0x390 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x465b49 Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f759d122c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000073bfa8 RCX: 0000000000465b49 RDX: 000000000000000c RSI: 0000000020000080 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f759d1236bc R13: 00000000004ca27c R14: 000000000070de40 R15: 00000000ffffffff Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: 0x39400000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) Fixes: 7452a3c745a2 ("IB/uverbs: Allow RDMA_REMOVE_DESTROY to work concurrently with disassociate") Link: https://lore.kernel.org/r/20200527135534.482279-1-leon@kernel.org Signed-off-by: Maor Gottlieb <maorg@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit c85f4abe66bea0b5db8d28d55da760c4fe0a0301 ]

Fix use after free when user user space request uobject concurrently for
the same object, within the RCU grace period.

In that case, remove_handle_idr_uobject() is called twice and we will have
an extra put on the uobject which cause use after free.  Fix it by leaving
the uobject write locked after it was removed from the idr.

Call to rdma_lookup_put_uobject with UVERBS_LOOKUP_DESTROY instead of
UVERBS_LOOKUP_WRITE will do the work.

  refcount_t: underflow; use-after-free.
  WARNING: CPU: 0 PID: 1381 at lib/refcount.c:28 refcount_warn_saturate+0xfe/0x1a0
  Kernel panic - not syncing: panic_on_warn set ...
  CPU: 0 PID: 1381 Comm: syz-executor.0 Not tainted 5.5.0-rc3 #8
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
  Call Trace:
   dump_stack+0x94/0xce
   panic+0x234/0x56f
   __warn+0x1cc/0x1e1
   report_bug+0x200/0x310
   fixup_bug.part.11+0x32/0x80
   do_error_trap+0xd3/0x100
   do_invalid_op+0x31/0x40
   invalid_op+0x1e/0x30
  RIP: 0010:refcount_warn_saturate+0xfe/0x1a0
  Code: 0f 0b eb 9b e8 23 f6 6d ff 80 3d 6c d4 19 03 00 75 8d e8 15 f6 6d ff 48 c7 c7 c0 02 55 bd c6 05 57 d4 19 03 01 e8 a2 58 49 ff <0f> 0b e9 6e ff ff ff e8 f6 f5 6d ff 80 3d 42 d4 19 03 00 0f 85 5c
  RSP: 0018:ffffc90002df7b98 EFLAGS: 00010282
  RAX: 0000000000000000 RBX: ffff88810f6a193c RCX: ffffffffba649009
  RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88811b0283cc
  RBP: 0000000000000003 R08: ffffed10236060e3 R09: ffffed10236060e3
  R10: 0000000000000001 R11: ffffed10236060e2 R12: ffff88810f6a193c
  R13: ffffc90002df7d60 R14: 0000000000000000 R15: ffff888116ae6a08
   uverbs_uobject_put+0xfd/0x140
   __uobj_perform_destroy+0x3d/0x60
   ib_uverbs_close_xrcd+0x148/0x170
   ib_uverbs_write+0xaa5/0xdf0
   __vfs_write+0x7c/0x100
   vfs_write+0x168/0x4a0
   ksys_write+0xc8/0x200
   do_syscall_64+0x9c/0x390
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x465b49
  Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007f759d122c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
  RAX: ffffffffffffffda RBX: 000000000073bfa8 RCX: 0000000000465b49
  RDX: 000000000000000c RSI: 0000000020000080 RDI: 0000000000000003
  RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f759d1236bc
  R13: 00000000004ca27c R14: 000000000070de40 R15: 00000000ffffffff
  Dumping ftrace buffer:
     (ftrace buffer empty)
  Kernel Offset: 0x39400000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)

Fixes: 7452a3c745a2 ("IB/uverbs: Allow RDMA_REMOVE_DESTROY to work concurrently with disassociate")
Link: https://lore.kernel.org/r/20200527135534.482279-1-leon@kernel.org
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>