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22 Commits

Author SHA1 Message Date
Chuck Lever
d74226e03d net/handshake: Fix handshake_req_destroy_test1 
[ Upstream commit 4e1d71cabb ]

Recently, handshake_req_destroy_test1 started failing:

Expected handshake_req_destroy_test == req, but
    handshake_req_destroy_test == 0000000000000000
    req == 0000000060f99b40
not ok 11 req_destroy works

This is because "sock_release(sock)" was replaced with "fput(filp)"
to address a memory leak. Note that sock_release() is synchronous
but fput() usually delays the final close and clean-up.

The delay is not consequential in the other cases that were changed
but handshake_req_destroy_test1 is testing that handshake_req_cancel()
followed by closing the file actually does call the ->hp_destroy
method. Thus the PTR_EQ test at the end has to be sure that the
final close is complete before it checks the pointer.

We cannot use a completion here because if ->hp_destroy is never
called (ie, there is an API bug) then the test will hang.

Reported by: Guenter Roeck <linux@roeck-us.net>
Closes: https://lore.kernel.org/netdev/ZcKDd1to4MPANCrn@tissot.1015granger.net/T/#mac5c6299f86799f1c71776f3a07f9c566c7c3c40
Fixes: 4a0f07d71b ("net/handshake: Fix memory leak in __sock_create() and sock_alloc_file()")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/170724699027.91401.7839730697326806733.stgit@oracle-102.nfsv4bat.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
 2024-02-23 09:24:50 +01:00
Moritz Wanzenböck
7798b59409 net/handshake: fix file ref count in handshake_nl_accept_doit() 
If req->hr_proto->hp_accept() fail, we call fput() twice:
Once in the error path, but also a second time because sock->file
is at that point already associated with the file descriptor. Once
the task exits, as it would probably do after receiving an error
reading from netlink, the fd is closed, calling fput() a second time.

To fix, we move installing the file after the error path for the
hp_accept() call. In the case of errors we simply put the unused fd.
In case of success we can use fd_install() to link the sock->file
to the reserved fd.

Fixes: 7ea9c1ec66 ("net/handshake: Fix handshake_dup() ref counting")
Signed-off-by: Moritz Wanzenböck <moritz.wanzenboeck@linbit.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20231019125847.276443-1-moritz.wanzenboeck@linbit.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2023-10-23 10:19:33 -07:00
Jinjie Ruan
4a0f07d71b net/handshake: Fix memory leak in __sock_create() and sock_alloc_file() 
When making CONFIG_DEBUG_KMEMLEAK=y and CONFIG_DEBUG_KMEMLEAK_AUTO_SCAN=y,
modprobe handshake-test and then rmmmod handshake-test, the below memory
leak is detected.

The struct socket_alloc which is allocated by alloc_inode_sb() in
__sock_create() is not freed. And the struct dentry which is allocated
by __d_alloc() in sock_alloc_file() is not freed.

Since fput() will call file->f_op->release() which is sock_close() here and
it will call __sock_release(). and fput() will call dput(dentry) to free
the struct dentry. So replace sock_release() with fput() to fix the
below memory leak. After applying this patch, the following memory leak is
never detected.

unreferenced object 0xffff888109165840 (size 768):
  comm "kunit_try_catch", pid 1852, jiffies 4294685807 (age 976.262s)
  hex dump (first 32 bytes):
    01 00 00 00 01 00 5a 5a 20 00 00 00 00 00 00 00  ......ZZ .......
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff8397993f>] sock_alloc_inode+0x1f/0x1b0
    [<ffffffff81a2cb5b>] alloc_inode+0x5b/0x1a0
    [<ffffffff81a32bed>] new_inode_pseudo+0xd/0x70
    [<ffffffff8397889c>] sock_alloc+0x3c/0x260
    [<ffffffff83979b46>] __sock_create+0x66/0x3d0
    [<ffffffffa0209ba2>] 0xffffffffa0209ba2
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff88810f472008 (size 192):
  comm "kunit_try_catch", pid 1852, jiffies 4294685808 (age 976.261s)
  hex dump (first 32 bytes):
    00 00 50 40 02 00 00 00 00 00 00 00 00 00 00 00  ..P@............
    00 00 00 00 00 00 00 00 08 20 47 0f 81 88 ff ff  ......... G.....
  backtrace:
    [<ffffffff81a1ff11>] __d_alloc+0x31/0x8a0
    [<ffffffff81a2910e>] d_alloc_pseudo+0xe/0x50
    [<ffffffff819d549e>] alloc_file_pseudo+0xce/0x210
    [<ffffffff83978582>] sock_alloc_file+0x42/0x1b0
    [<ffffffffa0209bbb>] 0xffffffffa0209bbb
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff88810958e580 (size 224):
  comm "kunit_try_catch", pid 1852, jiffies 4294685808 (age 976.261s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 03 00 2e 08 01 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff819d4b90>] alloc_empty_file+0x50/0x160
    [<ffffffff819d4cf9>] alloc_file+0x59/0x730
    [<ffffffff819d5524>] alloc_file_pseudo+0x154/0x210
    [<ffffffff83978582>] sock_alloc_file+0x42/0x1b0
    [<ffffffffa0209bbb>] 0xffffffffa0209bbb
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff88810926dc88 (size 192):
  comm "kunit_try_catch", pid 1854, jiffies 4294685809 (age 976.271s)
  hex dump (first 32 bytes):
    00 00 50 40 02 00 00 00 00 00 00 00 00 00 00 00  ..P@............
    00 00 00 00 00 00 00 00 88 dc 26 09 81 88 ff ff  ..........&.....
  backtrace:
    [<ffffffff81a1ff11>] __d_alloc+0x31/0x8a0
    [<ffffffff81a2910e>] d_alloc_pseudo+0xe/0x50
    [<ffffffff819d549e>] alloc_file_pseudo+0xce/0x210
    [<ffffffff83978582>] sock_alloc_file+0x42/0x1b0
    [<ffffffffa0208fdc>] 0xffffffffa0208fdc
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff88810a241380 (size 224):
  comm "kunit_try_catch", pid 1854, jiffies 4294685809 (age 976.271s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 03 00 2e 08 01 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff819d4b90>] alloc_empty_file+0x50/0x160
    [<ffffffff819d4cf9>] alloc_file+0x59/0x730
    [<ffffffff819d5524>] alloc_file_pseudo+0x154/0x210
    [<ffffffff83978582>] sock_alloc_file+0x42/0x1b0
    [<ffffffffa0208fdc>] 0xffffffffa0208fdc
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff888109165040 (size 768):
  comm "kunit_try_catch", pid 1856, jiffies 4294685811 (age 976.269s)
  hex dump (first 32 bytes):
    01 00 00 00 01 00 5a 5a 20 00 00 00 00 00 00 00  ......ZZ .......
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff8397993f>] sock_alloc_inode+0x1f/0x1b0
    [<ffffffff81a2cb5b>] alloc_inode+0x5b/0x1a0
    [<ffffffff81a32bed>] new_inode_pseudo+0xd/0x70
    [<ffffffff8397889c>] sock_alloc+0x3c/0x260
    [<ffffffff83979b46>] __sock_create+0x66/0x3d0
    [<ffffffffa0208860>] 0xffffffffa0208860
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff88810926d568 (size 192):
  comm "kunit_try_catch", pid 1856, jiffies 4294685811 (age 976.269s)
  hex dump (first 32 bytes):
    00 00 50 40 02 00 00 00 00 00 00 00 00 00 00 00  ..P@............
    00 00 00 00 00 00 00 00 68 d5 26 09 81 88 ff ff  ........h.&.....
  backtrace:
    [<ffffffff81a1ff11>] __d_alloc+0x31/0x8a0
    [<ffffffff81a2910e>] d_alloc_pseudo+0xe/0x50
    [<ffffffff819d549e>] alloc_file_pseudo+0xce/0x210
    [<ffffffff83978582>] sock_alloc_file+0x42/0x1b0
    [<ffffffffa0208879>] 0xffffffffa0208879
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff88810a240580 (size 224):
  comm "kunit_try_catch", pid 1856, jiffies 4294685811 (age 976.347s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 03 00 2e 08 01 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff819d4b90>] alloc_empty_file+0x50/0x160
    [<ffffffff819d4cf9>] alloc_file+0x59/0x730
    [<ffffffff819d5524>] alloc_file_pseudo+0x154/0x210
    [<ffffffff83978582>] sock_alloc_file+0x42/0x1b0
    [<ffffffffa0208879>] 0xffffffffa0208879
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff888109164c40 (size 768):
  comm "kunit_try_catch", pid 1858, jiffies 4294685816 (age 976.342s)
  hex dump (first 32 bytes):
    01 00 00 00 01 00 5a 5a 20 00 00 00 00 00 00 00  ......ZZ .......
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff8397993f>] sock_alloc_inode+0x1f/0x1b0
    [<ffffffff81a2cb5b>] alloc_inode+0x5b/0x1a0
    [<ffffffff81a32bed>] new_inode_pseudo+0xd/0x70
    [<ffffffff8397889c>] sock_alloc+0x3c/0x260
    [<ffffffff83979b46>] __sock_create+0x66/0x3d0
    [<ffffffffa0208541>] 0xffffffffa0208541
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff88810926cd18 (size 192):
  comm "kunit_try_catch", pid 1858, jiffies 4294685816 (age 976.342s)
  hex dump (first 32 bytes):
    00 00 50 40 02 00 00 00 00 00 00 00 00 00 00 00  ..P@............
    00 00 00 00 00 00 00 00 18 cd 26 09 81 88 ff ff  ..........&.....
  backtrace:
    [<ffffffff81a1ff11>] __d_alloc+0x31/0x8a0
    [<ffffffff81a2910e>] d_alloc_pseudo+0xe/0x50
    [<ffffffff819d549e>] alloc_file_pseudo+0xce/0x210
    [<ffffffff83978582>] sock_alloc_file+0x42/0x1b0
    [<ffffffffa020855a>] 0xffffffffa020855a
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff88810a240200 (size 224):
  comm "kunit_try_catch", pid 1858, jiffies 4294685816 (age 976.342s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 03 00 2e 08 01 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff819d4b90>] alloc_empty_file+0x50/0x160
    [<ffffffff819d4cf9>] alloc_file+0x59/0x730
    [<ffffffff819d5524>] alloc_file_pseudo+0x154/0x210
    [<ffffffff83978582>] sock_alloc_file+0x42/0x1b0
    [<ffffffffa020855a>] 0xffffffffa020855a
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff888109164840 (size 768):
  comm "kunit_try_catch", pid 1860, jiffies 4294685817 (age 976.416s)
  hex dump (first 32 bytes):
    01 00 00 00 01 00 5a 5a 20 00 00 00 00 00 00 00  ......ZZ .......
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff8397993f>] sock_alloc_inode+0x1f/0x1b0
    [<ffffffff81a2cb5b>] alloc_inode+0x5b/0x1a0
    [<ffffffff81a32bed>] new_inode_pseudo+0xd/0x70
    [<ffffffff8397889c>] sock_alloc+0x3c/0x260
    [<ffffffff83979b46>] __sock_create+0x66/0x3d0
    [<ffffffffa02093e2>] 0xffffffffa02093e2
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff88810926cab8 (size 192):
  comm "kunit_try_catch", pid 1860, jiffies 4294685817 (age 976.416s)
  hex dump (first 32 bytes):
    00 00 50 40 02 00 00 00 00 00 00 00 00 00 00 00  ..P@............
    00 00 00 00 00 00 00 00 b8 ca 26 09 81 88 ff ff  ..........&.....
  backtrace:
    [<ffffffff81a1ff11>] __d_alloc+0x31/0x8a0
    [<ffffffff81a2910e>] d_alloc_pseudo+0xe/0x50
    [<ffffffff819d549e>] alloc_file_pseudo+0xce/0x210
    [<ffffffff83978582>] sock_alloc_file+0x42/0x1b0
    [<ffffffffa02093fb>] 0xffffffffa02093fb
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff88810a240040 (size 224):
  comm "kunit_try_catch", pid 1860, jiffies 4294685817 (age 976.416s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 03 00 2e 08 01 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff819d4b90>] alloc_empty_file+0x50/0x160
    [<ffffffff819d4cf9>] alloc_file+0x59/0x730
    [<ffffffff819d5524>] alloc_file_pseudo+0x154/0x210
    [<ffffffff83978582>] sock_alloc_file+0x42/0x1b0
    [<ffffffffa02093fb>] 0xffffffffa02093fb
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff888109166440 (size 768):
  comm "kunit_try_catch", pid 1862, jiffies 4294685819 (age 976.489s)
  hex dump (first 32 bytes):
    01 00 00 00 01 00 5a 5a 20 00 00 00 00 00 00 00  ......ZZ .......
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff8397993f>] sock_alloc_inode+0x1f/0x1b0
    [<ffffffff81a2cb5b>] alloc_inode+0x5b/0x1a0
    [<ffffffff81a32bed>] new_inode_pseudo+0xd/0x70
    [<ffffffff8397889c>] sock_alloc+0x3c/0x260
    [<ffffffff83979b46>] __sock_create+0x66/0x3d0
    [<ffffffffa02097c1>] 0xffffffffa02097c1
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff88810926c398 (size 192):
  comm "kunit_try_catch", pid 1862, jiffies 4294685819 (age 976.489s)
  hex dump (first 32 bytes):
    00 00 50 40 02 00 00 00 00 00 00 00 00 00 00 00  ..P@............
    00 00 00 00 00 00 00 00 98 c3 26 09 81 88 ff ff  ..........&.....
  backtrace:
    [<ffffffff81a1ff11>] __d_alloc+0x31/0x8a0
    [<ffffffff81a2910e>] d_alloc_pseudo+0xe/0x50
    [<ffffffff819d549e>] alloc_file_pseudo+0xce/0x210
    [<ffffffff83978582>] sock_alloc_file+0x42/0x1b0
    [<ffffffffa02097da>] 0xffffffffa02097da
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff888107e0b8c0 (size 224):
  comm "kunit_try_catch", pid 1862, jiffies 4294685819 (age 976.489s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 03 00 2e 08 01 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff819d4b90>] alloc_empty_file+0x50/0x160
    [<ffffffff819d4cf9>] alloc_file+0x59/0x730
    [<ffffffff819d5524>] alloc_file_pseudo+0x154/0x210
    [<ffffffff83978582>] sock_alloc_file+0x42/0x1b0
    [<ffffffffa02097da>] 0xffffffffa02097da
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff888109164440 (size 768):
  comm "kunit_try_catch", pid 1864, jiffies 4294685821 (age 976.487s)
  hex dump (first 32 bytes):
    01 00 00 00 01 00 5a 5a 20 00 00 00 00 00 00 00  ......ZZ .......
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff8397993f>] sock_alloc_inode+0x1f/0x1b0
    [<ffffffff81a2cb5b>] alloc_inode+0x5b/0x1a0
    [<ffffffff81a32bed>] new_inode_pseudo+0xd/0x70
    [<ffffffff8397889c>] sock_alloc+0x3c/0x260
    [<ffffffff83979b46>] __sock_create+0x66/0x3d0
    [<ffffffffa020824e>] 0xffffffffa020824e
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff88810f4cf698 (size 192):
  comm "kunit_try_catch", pid 1864, jiffies 4294685821 (age 976.501s)
  hex dump (first 32 bytes):
    00 00 50 40 02 00 00 00 00 00 00 00 00 00 00 00  ..P@............
    00 00 00 00 00 00 00 00 98 f6 4c 0f 81 88 ff ff  ..........L.....
  backtrace:
    [<ffffffff81a1ff11>] __d_alloc+0x31/0x8a0
    [<ffffffff81a2910e>] d_alloc_pseudo+0xe/0x50
    [<ffffffff819d549e>] alloc_file_pseudo+0xce/0x210
    [<ffffffff83978582>] sock_alloc_file+0x42/0x1b0
    [<ffffffffa0208267>] 0xffffffffa0208267
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff888107e0b000 (size 224):
  comm "kunit_try_catch", pid 1864, jiffies 4294685821 (age 976.501s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 03 00 2e 08 01 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff819d4b90>] alloc_empty_file+0x50/0x160
    [<ffffffff819d4cf9>] alloc_file+0x59/0x730
    [<ffffffff819d5524>] alloc_file_pseudo+0x154/0x210
    [<ffffffff83978582>] sock_alloc_file+0x42/0x1b0
    [<ffffffffa0208267>] 0xffffffffa0208267
    [<ffffffff829cf03a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81236fc6>] kthread+0x2b6/0x380
    [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
    [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20

Fixes: 88232ec1ec ("net/handshake: Add Kunit tests for the handshake consumer API")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2023-09-20 11:54:49 +01:00
Eric Dumazet
82ba0ff7bf net/handshake: fix null-ptr-deref in handshake_nl_done_doit() 
We should not call trace_handshake_cmd_done_err() if socket lookup has failed.

Also we should call trace_handshake_cmd_done_err() before releasing the file,
otherwise dereferencing sock->sk can return garbage.

This also reverts 7afc6d0a10 ("net/handshake: Fix uninitialized local variable")

Unable to handle kernel paging request at virtual address dfff800000000003
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
Mem abort info:
ESR = 0x0000000096000005
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x05: level 1 translation fault
Data abort info:
ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[dfff800000000003] address between user and kernel address ranges
Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 5986 Comm: syz-executor292 Not tainted 6.5.0-rc7-syzkaller-gfe4469582053 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : handshake_nl_done_doit+0x198/0x9c8 net/handshake/netlink.c:193
lr : handshake_nl_done_doit+0x180/0x9c8
sp : ffff800096e37180
x29: ffff800096e37200 x28: 1ffff00012dc6e34 x27: dfff800000000000
x26: ffff800096e373d0 x25: 0000000000000000 x24: 00000000ffffffa8
x23: ffff800096e373f0 x22: 1ffff00012dc6e38 x21: 0000000000000000
x20: ffff800096e371c0 x19: 0000000000000018 x18: 0000000000000000
x17: 0000000000000000 x16: ffff800080516cc4 x15: 0000000000000001
x14: 1fffe0001b14aa3b x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000003
x8 : 0000000000000003 x7 : ffff800080afe47c x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800080a88078
x2 : 0000000000000001 x1 : 00000000ffffffa8 x0 : 0000000000000000
Call trace:
handshake_nl_done_doit+0x198/0x9c8 net/handshake/netlink.c:193
genl_family_rcv_msg_doit net/netlink/genetlink.c:970 [inline]
genl_family_rcv_msg net/netlink/genetlink.c:1050 [inline]
genl_rcv_msg+0x96c/0xc50 net/netlink/genetlink.c:1067
netlink_rcv_skb+0x214/0x3c4 net/netlink/af_netlink.c:2549
genl_rcv+0x38/0x50 net/netlink/genetlink.c:1078
netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0x660/0x8d4 net/netlink/af_netlink.c:1365
netlink_sendmsg+0x834/0xb18 net/netlink/af_netlink.c:1914
sock_sendmsg_nosec net/socket.c:725 [inline]
sock_sendmsg net/socket.c:748 [inline]
____sys_sendmsg+0x56c/0x840 net/socket.c:2494
___sys_sendmsg net/socket.c:2548 [inline]
__sys_sendmsg+0x26c/0x33c net/socket.c:2577
__do_sys_sendmsg net/socket.c:2586 [inline]
__se_sys_sendmsg net/socket.c:2584 [inline]
__arm64_sys_sendmsg+0x80/0x94 net/socket.c:2584
__invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
el0_svc+0x58/0x16c arch/arm64/kernel/entry-common.c:678
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591
Code: 12800108 b90043e8 910062b3 d343fe68 (387b6908)

Fixes: 3b3009ea8a ("net/handshake: Create a NETLINK service for handling handshake requests")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2023-09-01 07:25:14 +01:00
Chuck Lever
b470985c76 net/handshake: Trace events for TLS Alert helpers 
Add observability for the new TLS Alert infrastructure.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/169047947409.5241.14548832149596892717.stgit@oracle-102.nfsv4bat.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2023-07-28 14:07:59 -07:00
Chuck Lever
39d0e38dcc net/handshake: Add helpers for parsing incoming TLS Alerts 
Kernel TLS consumers can replace common TLS Alert parsing code with
these helpers.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/169047942074.5241.13791647439480672048.stgit@oracle-102.nfsv4bat.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2023-07-28 14:07:59 -07:00
Chuck Lever
35b1b538d4 net/handshake: Add API for sending TLS Closure alerts 
This helper sends an alert only if a TLS session was established.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/169047936730.5241.618595693821012638.stgit@oracle-102.nfsv4bat.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2023-07-28 14:07:59 -07:00
Jakub Kicinski
173780ff18 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 
Cross-merge networking fixes after downstream PR.

Conflicts:

include/linux/mlx5/driver.h
  617f5db1a6 ("RDMA/mlx5: Fix affinity assignment")
  dc13180824 ("net/mlx5: Enable devlink port for embedded cpu VF vports")
https://lore.kernel.org/all/20230613125939.595e50b8@canb.auug.org.au/

tools/testing/selftests/net/mptcp/mptcp_join.sh
  47867f0a7e ("selftests: mptcp: join: skip check if MIB counter not supported")
  425ba80312 ("selftests: mptcp: join: support RM_ADDR for used endpoints or not")
  45b1a1227a ("mptcp: introduces more address related mibs")
  0639fa230a ("selftests: mptcp: add explicit check for new mibs")
https://lore.kernel.org/netdev/20230609-upstream-net-20230610-mptcp-selftests-support-old-kernels-part-3-v1-0-2896fe2ee8a3@tessares.net/

No adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2023-06-15 22:19:41 -07:00
Lin Ma
361b6889ae net/handshake: remove fput() that causes use-after-free 
A reference underflow is found in TLS handshake subsystem that causes a
direct use-after-free. Part of the crash log is like below:

[    2.022114] ------------[ cut here ]------------
[    2.022193] refcount_t: underflow; use-after-free.
[    2.022288] WARNING: CPU: 0 PID: 60 at lib/refcount.c:28 refcount_warn_saturate+0xbe/0x110
[    2.022432] Modules linked in:
[    2.022848] RIP: 0010:refcount_warn_saturate+0xbe/0x110
[    2.023231] RSP: 0018:ffffc900001bfe18 EFLAGS: 00000286
[    2.023325] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00000000ffffdfff
[    2.023438] RDX: 0000000000000000 RSI: 00000000ffffffea RDI: 0000000000000001
[    2.023555] RBP: ffff888004c20098 R08: ffffffff82b392c8 R09: 00000000ffffdfff
[    2.023693] R10: ffffffff82a592e0 R11: ffffffff82b092e0 R12: ffff888004c200d8
[    2.023813] R13: 0000000000000000 R14: ffff888004c20000 R15: ffffc90000013ca8
[    2.023930] FS:  0000000000000000(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000
[    2.024062] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    2.024161] CR2: ffff888003601000 CR3: 0000000002a2e000 CR4: 00000000000006f0
[    2.024275] Call Trace:
[    2.024322]  <TASK>
[    2.024367]  ? __warn+0x7f/0x130
[    2.024430]  ? refcount_warn_saturate+0xbe/0x110
[    2.024513]  ? report_bug+0x199/0x1b0
[    2.024585]  ? handle_bug+0x3c/0x70
[    2.024676]  ? exc_invalid_op+0x18/0x70
[    2.024750]  ? asm_exc_invalid_op+0x1a/0x20
[    2.024830]  ? refcount_warn_saturate+0xbe/0x110
[    2.024916]  ? refcount_warn_saturate+0xbe/0x110
[    2.024998]  __tcp_close+0x2f4/0x3d0
[    2.025065]  ? __pfx_kunit_generic_run_threadfn_adapter+0x10/0x10
[    2.025168]  tcp_close+0x1f/0x70
[    2.025231]  inet_release+0x33/0x60
[    2.025297]  sock_release+0x1f/0x80
[    2.025361]  handshake_req_cancel_test2+0x100/0x2d0
[    2.025457]  kunit_try_run_case+0x4c/0xa0
[    2.025532]  kunit_generic_run_threadfn_adapter+0x15/0x20
[    2.025644]  kthread+0xe1/0x110
[    2.025708]  ? __pfx_kthread+0x10/0x10
[    2.025780]  ret_from_fork+0x2c/0x50

One can enable CONFIG_NET_HANDSHAKE_KUNIT_TEST config to reproduce above
crash.

The root cause of this bug is that the commit 1ce77c998f
("net/handshake: Unpin sock->file if a handshake is cancelled") adds one
additional fput() function. That patch claims that the fput() is used to
enable sock->file to be freed even when user space never calls DONE.

However, it seems that the intended DONE routine will never give an
additional fput() of ths sock->file. The existing two of them are just
used to balance the reference added in sockfd_lookup().

This patch revert the mentioned commit to avoid the use-after-free. The
patched kernel could successfully pass the KUNIT test and boot to shell.

[    0.733613]     # Subtest: Handshake API tests
[    0.734029]     1..11
[    0.734255]         KTAP version 1
[    0.734542]         # Subtest: req_alloc API fuzzing
[    0.736104]         ok 1 handshake_req_alloc NULL proto
[    0.736114]         ok 2 handshake_req_alloc CLASS_NONE
[    0.736559]         ok 3 handshake_req_alloc CLASS_MAX
[    0.737020]         ok 4 handshake_req_alloc no callbacks
[    0.737488]         ok 5 handshake_req_alloc no done callback
[    0.737988]         ok 6 handshake_req_alloc excessive privsize
[    0.738529]         ok 7 handshake_req_alloc all good
[    0.739036]     # req_alloc API fuzzing: pass:7 fail:0 skip:0 total:7
[    0.739444]     ok 1 req_alloc API fuzzing
[    0.740065]     ok 2 req_submit NULL req arg
[    0.740436]     ok 3 req_submit NULL sock arg
[    0.740834]     ok 4 req_submit NULL sock->file
[    0.741236]     ok 5 req_lookup works
[    0.741621]     ok 6 req_submit max pending
[    0.741974]     ok 7 req_submit multiple
[    0.742382]     ok 8 req_cancel before accept
[    0.742764]     ok 9 req_cancel after accept
[    0.743151]     ok 10 req_cancel after done
[    0.743510]     ok 11 req_destroy works
[    0.743882] # Handshake API tests: pass:11 fail:0 skip:0 total:11
[    0.744205] # Totals: pass:17 fail:0 skip:0 total:17

Acked-by: Chuck Lever <chuck.lever@oracle.com>
Fixes: 1ce77c998f ("net/handshake: Unpin sock->file if a handshake is cancelled")
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Link: https://lore.kernel.org/r/20230613083204.633896-1-linma@zju.edu.cn
Link: https://lore.kernel.org/r/20230614015249.987448-1-linma@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2023-06-14 22:26:37 -07:00
Jakub Kicinski
9b66ee06e5 net: ynl: prefix uAPI header include with uapi/ 
To keep things simple we used to include the uAPI header
in the kernel in the #include <linux/$family.h> format.
This works well enough, most of the genl families should
have headers in include/net/ so linux/$family.h ends up
referring to the uAPI header, anyway. And if it doesn't
no big deal, we'll just include more info than we need.

Unless that is there is a naming conflict. Someone recently
created include/linux/psp.h which will be a problem when
supporting the PSP protocol. (I'm talking about
work-in-progress patches, but it's just a proof that assuming
lack of name conflicts was overly optimistic.)

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2023-05-26 10:30:14 +01:00
Chuck Lever
26fb5480a2 net/handshake: Enable the SNI extension to work properly 
Enable the upper layer protocol to specify the SNI peername. This
avoids the need for tlshd to use a DNS lookup, which can return a
hostname that doesn't match the incoming certificate's SubjectName.

Fixes: 2fd5532044 ("net/handshake: Add a kernel API for requesting a TLSv1.3 handshake")
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2023-05-24 22:05:24 -07:00
Chuck Lever
1ce77c998f net/handshake: Unpin sock->file if a handshake is cancelled 
If user space never calls DONE, sock->file's reference count remains
elevated. Enable sock->file to be freed eventually in this case.

Reported-by: Jakub Kacinski <kuba@kernel.org>
Fixes: 3b3009ea8a ("net/handshake: Create a NETLINK service for handling handshake requests")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2023-05-24 22:05:24 -07:00
Chuck Lever
fc490880e3 net/handshake: handshake_genl_notify() shouldn't ignore @flags 
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: 3b3009ea8a ("net/handshake: Create a NETLINK service for handling handshake requests")
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2023-05-24 22:05:24 -07:00
Chuck Lever
7afc6d0a10 net/handshake: Fix uninitialized local variable 
trace_handshake_cmd_done_err() simply records the pointer in @req,
so initializing it to NULL is sufficient and safe.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: 3b3009ea8a ("net/handshake: Create a NETLINK service for handling handshake requests")
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2023-05-24 22:05:24 -07:00
Chuck Lever
7ea9c1ec66 net/handshake: Fix handshake_dup() ref counting 
If get_unused_fd_flags() fails, we ended up calling fput(sock->file)
twice.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Fixes: 3b3009ea8a ("net/handshake: Create a NETLINK service for handling handshake requests")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2023-05-24 22:05:24 -07:00
Chuck Lever
a095326e2c net/handshake: Remove unneeded check from handshake_dup() 
handshake_req_submit() now verifies that the socket has a file.

Fixes: 3b3009ea8a ("net/handshake: Create a NETLINK service for handling handshake requests")
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2023-05-24 22:05:23 -07:00
Chuck Lever
18c40a1cc1 net/handshake: Fix sock->file allocation 
sock->file = sock_alloc_file(sock, O_NONBLOCK, NULL);
	^^^^                         ^^^^

sock_alloc_file() calls release_sock() on error but the left hand
side of the assignment dereferences "sock".  This isn't the bug and
I didn't report this earlier because there is an assert that it
doesn't fail.

net/handshake/handshake-test.c:221 handshake_req_submit_test4() error: dereferencing freed memory 'sock'
net/handshake/handshake-test.c:233 handshake_req_submit_test4() warn: 'req' was already freed.
net/handshake/handshake-test.c:254 handshake_req_submit_test5() error: dereferencing freed memory 'sock'
net/handshake/handshake-test.c:290 handshake_req_submit_test6() error: dereferencing freed memory 'sock'
net/handshake/handshake-test.c:321 handshake_req_cancel_test1() error: dereferencing freed memory 'sock'
net/handshake/handshake-test.c:355 handshake_req_cancel_test2() error: dereferencing freed memory 'sock'
net/handshake/handshake-test.c:367 handshake_req_cancel_test2() warn: 'req' was already freed.
net/handshake/handshake-test.c:395 handshake_req_cancel_test3() error: dereferencing freed memory 'sock'
net/handshake/handshake-test.c:407 handshake_req_cancel_test3() warn: 'req' was already freed.
net/handshake/handshake-test.c:451 handshake_req_destroy_test1() error: dereferencing freed memory 'sock'
net/handshake/handshake-test.c:463 handshake_req_destroy_test1() warn: 'req' was already freed.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: 88232ec1ec ("net/handshake: Add Kunit tests for the handshake consumer API")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/168451609436.45209.15407022385441542980.stgit@oracle-102.nfsv4bat.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2023-05-22 19:25:24 -07:00
Chuck Lever
b21c7ba6d9 net/handshake: Squelch allocation warning during Kunit test 
The "handshake_req_alloc excessive privsize" kunit test is intended
to check what happens when the maximum privsize is exceeded. The
WARN_ON_ONCE_GFP at mm/page_alloc.c:4744 can be disabled safely for
this test.

Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Fixes: 88232ec1ec ("net/handshake: Add Kunit tests for the handshake consumer API")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/168451636052.47152.9600443326570457947.stgit@oracle-102.nfsv4bat.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2023-05-22 19:24:52 -07:00
Geert Uytterhoeven
6aa445e396 net/handshake: Fix section mismatch in handshake_exit 
If CONFIG_NET_NS=n (e.g. m68k/defconfig):

    WARNING: modpost: vmlinux.o: section mismatch in reference: handshake_exit (section: .exit.text) -> handshake_genl_net_ops (section: .init.data)
    ERROR: modpost: Section mismatches detected.

Fix this by dropping the __net_initdata tag from handshake_genl_net_ops.

Fixes: 3b3009ea8a ("net/handshake: Create a NETLINK service for handling handshake requests")
Reported-by: noreply@ellerman.id.au
Closes: http://kisskb.ellerman.id.au/kisskb/buildresult/14912987
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20230420173723.3773434-1-geert@linux-m68k.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2023-04-21 20:24:57 -07:00
Chuck Lever
88232ec1ec net/handshake: Add Kunit tests for the handshake consumer API 
These verify the API contracts and help exercise lifetime rules for
consumer sockets and handshake_req structures.

One way to run these tests:

./tools/testing/kunit/kunit.py run --kunitconfig ./net/handshake/.kunitconfig

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2023-04-19 18:48:48 -07:00
Chuck Lever
2fd5532044 net/handshake: Add a kernel API for requesting a TLSv1.3 handshake 
To enable kernel consumers of TLS to request a TLS handshake, add
support to net/handshake/ to request a handshake upcall.

This patch also acts as a template for adding handshake upcall
support for other kernel transport layer security providers.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2023-04-19 18:48:48 -07:00
Chuck Lever
3b3009ea8a net/handshake: Create a NETLINK service for handling handshake requests 
When a kernel consumer needs a transport layer security session, it
first needs a handshake to negotiate and establish a session. This
negotiation can be done in user space via one of the several
existing library implementations, or it can be done in the kernel.

No in-kernel handshake implementations yet exist. In their absence,
we add a netlink service that can:

a. Notify a user space daemon that a handshake is needed.

b. Once notified, the daemon calls the kernel back via this
   netlink service to get the handshake parameters, including an
   open socket on which to establish the session.

c. Once the handshake is complete, the daemon reports the
   session status and other information via a second netlink
   operation. This operation marks that it is safe for the
   kernel to use the open socket and the security session
   established there.

The notification service uses a multicast group. Each handshake
mechanism (eg, tlshd) adopts its own group number so that the
handshake services are completely independent of one another. The
kernel can then tell via netlink_has_listeners() whether a handshake
service is active and prepared to handle a handshake request.

A new netlink operation, ACCEPT, acts like accept(2) in that it
instantiates a file descriptor in the user space daemon's fd table.
If this operation is successful, the reply carries the fd number,
which can be treated as an open and ready file descriptor.

While user space is performing the handshake, the kernel keeps its
muddy paws off the open socket. A second new netlink operation,
DONE, indicates that the user space daemon is finished with the
socket and it is safe for the kernel to use again. The operation
also indicates whether a session was established successfully.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2023-04-19 18:48:48 -07:00