linux-toradex.git/net/rds/rdma.c, branch v6.19-rc2

net/rds: fix possible cp null dereference

2024-03-29T19:04:09+00:00

cp might be null, calling cp->cp_conn would produce null dereference

[Simon Horman adds:]

Analysis:

* cp is a parameter of __rds_rdma_map and is not reassigned.

* The following call-sites pass a NULL cp argument to __rds_rdma_map()

  - rds_get_mr()
  - rds_get_mr_for_dest

* Prior to the code above, the following assumes that cp may be NULL
  (which is indicative, but could itself be unnecessary)

	trans_private = rs->rs_transport->get_mr(
		sg, nents, rs, &mr->r_key, cp ? cp->cp_conn : NULL,
		args->vec.addr, args->vec.bytes,
		need_odp ? ODP_ZEROBASED : ODP_NOT_NEEDED);

* The code modified by this patch is guarded by IS_ERR(trans_private),
  where trans_private is assigned as per the previous point in this analysis.

  The only implementation of get_mr that I could locate is rds_ib_get_mr()
  which can return an ERR_PTR if the conn (4th) argument is NULL.

* ret is set to PTR_ERR(trans_private).
  rds_ib_get_mr can return ERR_PTR(-ENODEV) if the conn (4th) argument is NULL.
  Thus ret may be -ENODEV in which case the code in question will execute.

Conclusion:
* cp may be NULL at the point where this patch adds a check;
  this patch does seem to address a possible bug

Fixes: c055fc00c07b ("net/rds: fix WARNING in rds_conn_connect_if_down")
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Mahmoud Adam 
Reviewed-by: Simon Horman 
Link: https://lore.kernel.org/r/20240326153132.55580-1-mngyadam@amazon.com
Signed-off-by: Jakub Kicinski

net/rds: fix WARNING in rds_conn_connect_if_down

2024-03-06T11:58:42+00:00

If connection isn't established yet, get_mr() will fail, trigger connection after
get_mr().

Fixes: 584a8279a44a ("RDS: RDMA: return appropriate error on rdma map failures")
Reported-and-tested-by: syzbot+d4faee732755bba9838e@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis 
Signed-off-by: David S. Miller

net/rds: Use PTR_ERR instead of IS_ERR for rdsdebug()

2022-08-01T10:45:15+00:00

If 'local_odp_mr->r_trans_private' is a error code,
it is better to print the error code than to print
the value of IS_ERR().

Signed-off-by: Li Qiong 
Signed-off-by: David S. Miller

net/rds: restrict iovecs length for RDS_CMSG_RDMA_ARGS

2021-02-02T16:44:08+00:00

syzbot found WARNING in rds_rdma_extra_size [1] when RDS_CMSG_RDMA_ARGS
control message is passed with user-controlled
0x40001 bytes of args->nr_local, causing order >= MAX_ORDER condition.

The exact value 0x40001 can be checked with UIO_MAXIOV which is 0x400.
So for kcalloc() 0x400 iovecs with sizeof(struct rds_iovec) = 0x10
is the closest limit, with 0x10 leftover.

Same condition is currently done in rds_cmsg_rdma_args().

[1] WARNING: mm/page_alloc.c:5011
[..]
Call Trace:
 alloc_pages_current+0x18c/0x2a0 mm/mempolicy.c:2267
 alloc_pages include/linux/gfp.h:547 [inline]
 kmalloc_order+0x2e/0xb0 mm/slab_common.c:837
 kmalloc_order_trace+0x14/0x120 mm/slab_common.c:853
 kmalloc_array include/linux/slab.h:592 [inline]
 kcalloc include/linux/slab.h:621 [inline]
 rds_rdma_extra_size+0xb2/0x3b0 net/rds/rdma.c:568
 rds_rm_size net/rds/send.c:928 [inline]

Reported-by: syzbot+1bd2b07f93745fa38425@syzkaller.appspotmail.com
Signed-off-by: Sabyrzhan Tasbolatov 
Acked-by: Santosh Shilimkar 
Link: https://lore.kernel.org/r/20210201203233.1324704-1-snovitoll@gmail.com
Signed-off-by: Jakub Kicinski

RDS: drop double zeroing

2020-09-21T02:09:11+00:00

sg_init_table zeroes its first argument, so the allocation of that argument
doesn't have to.

the semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// 
@@
expression x,n,flags;
@@

x =
- kcalloc
+ kmalloc_array
  (n,sizeof(*x),flags)
...
sg_init_table(x,n)
// 

Signed-off-by: Julia Lawall 
Signed-off-by: David S. Miller

net: pass a sockptr_t into ->setsockopt

2020-07-24T22:41:54+00:00

Rework the remaining setsockopt code to pass a sockptr_t instead of a
plain user pointer.  This removes the last remaining set_fs(KERNEL_DS)
outside of architecture specific code.

Signed-off-by: Christoph Hellwig 
Acked-by: Stefan Schmidt  [ieee802154]
Acked-by: Matthieu Baerts 
Signed-off-by: David S. Miller

net/rds: Use ERR_PTR for rds_message_alloc_sgs()

2020-04-15T19:33:29+00:00

Returning the error code via a 'int *ret' when the function returns a
pointer is very un-kernely and causes gcc 10's static analysis to choke:

net/rds/message.c: In function ‘rds_message_map_pages’:
net/rds/message.c:358:10: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  358 |   return ERR_PTR(ret);

Use a typical ERR_PTR return instead.

Signed-off-by: Jason Gunthorpe 
Acked-by: Santosh Shilimkar 
Signed-off-by: David S. Miller

net/rds: Fix MR reference counting problem

2020-04-09T17:22:00+00:00

In rds_free_mr(), it calls rds_destroy_mr(mr) directly.  But this
defeats the purpose of reference counting and makes MR free handling
impossible.  It means that holding a reference does not guarantee that
it is safe to access some fields.  For example, In
rds_cmsg_rdma_dest(), it increases the ref count, unlocks and then
calls mr->r_trans->sync_mr().  But if rds_free_mr() (and
rds_destroy_mr()) is called in between (there is no lock preventing
this to happen), r_trans_private is set to NULL, causing a panic.
Similar issue is in rds_rdma_unuse().

Reported-by: zerons 
Signed-off-by: Ka-Cheong Poon 
Acked-by: Santosh Shilimkar 
Signed-off-by: David S. Miller

net/rds: Replace struct rds_mr's r_refcount with struct kref

2020-04-09T17:22:00+00:00

And removed rds_mr_put().

Signed-off-by: Ka-Cheong Poon 
Acked-by: Santosh Shilimkar 
Signed-off-by: David S. Miller

net/rds: Track user mapped pages through special API

2020-02-17T02:37:09+00:00

Convert net/rds to use the newly introduces pin_user_pages() API,
which properly sets FOLL_PIN. Setting FOLL_PIN is now required for
code that requires tracking of pinned pages.

Note that this effectively changes the code's behavior: it now
ultimately calls set_page_dirty_lock(), instead of set_page_dirty().
This is probably more accurate.

As Christoph Hellwig put it, "set_page_dirty() is only safe if we are
dealing with a file backed page where we have reference on the inode it
hangs off." [1]

[1] https://lore.kernel.org/r/20190723153640.GB720@lst.de

Cc: Hans Westgaard Ry 
Cc: Santosh Shilimkar 
Signed-off-by: Leon Romanovsky 
Signed-off-by: John Hubbard 
Acked-by: Santosh Shilimkar 
Signed-off-by: David S. Miller