[PATCH] RDMA/core: don't expose hw_counters outside of init net namespace

[PATCH] RDMA/core: don't expose hw_counters outside of init net namespace

[Roman Gushchin]

Commit 5fd8529350f0 ("RDMA/core: fix a NULL-pointer dereference in
hw_stat_device_show()") accidentally almost exposed hw counters
to non-init net namespaces. It didn't expose them fully, as an attempt
to read any of those counters leads to a crash like this one:

[42021.807566] BUG: kernel NULL pointer dereference, address: 0000000000000028
[42021.814463] #PF: supervisor read access in kernel mode
[42021.819549] #PF: error_code(0x0000) - not-present page
[42021.824636] PGD 0 P4D 0
[42021.827145] Oops: 0000 [#1] SMP PTI
[42021.830598] CPU: 82 PID: 2843922 Comm: switchto-defaul Kdump: loaded Tainted: G S      W I        XXX
[42021.841697] Hardware name: XXX
[42021.849619] RIP: 0010:hw_stat_device_show+0x1e/0x40 [ib_core]
[42021.855362] Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 49 89 d0 4c 8b 5e 20 48 8b 8f b8 04 00 00 48 81 c7 f0 fa ff ff <48> 8b 41 28 48 29 ce 48 83 c6 d0 48 c1 ee 04 69 d6 ab aa aa aa 48
[42021.873931] RSP: 0018:ffff97fe90f03da0 EFLAGS: 00010287
[42021.879108] RAX: ffff9406988a8c60 RBX: ffff940e1072d438 RCX: 0000000000000000
[42021.886169] RDX: ffff94085f1aa000 RSI: ffff93c6cbbdbcb0 RDI: ffff940c7517aef0
[42021.893230] RBP: ffff97fe90f03e70 R08: ffff94085f1aa000 R09: 0000000000000000
[42021.900294] R10: ffff94085f1aa000 R11: ffffffffc0775680 R12: ffffffff87ca2530
[42021.907355] R13: ffff940651602840 R14: ffff93c6cbbdbcb0 R15: ffff94085f1aa000
[42021.914418] FS:  00007fda1a3b9700(0000) GS:ffff94453fb80000(0000) knlGS:0000000000000000
[42021.922423] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[42021.928130] CR2: 0000000000000028 CR3: 00000042dcfb8003 CR4: 00000000003726f0
[42021.935194] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[42021.942257] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[42021.949324] Call Trace:
[42021.951756]  <TASK>
[42021.953842]  [<ffffffff86c58674>] ? show_regs+0x64/0x70
[42021.959030]  [<ffffffff86c58468>] ? __die+0x78/0xc0
[42021.963874]  [<ffffffff86c9ef75>] ? page_fault_oops+0x2b5/0x3b0
[42021.969749]  [<ffffffff87674b92>] ? exc_page_fault+0x1a2/0x3c0
[42021.975549]  [<ffffffff87801326>] ? asm_exc_page_fault+0x26/0x30
[42021.981517]  [<ffffffffc0775680>] ? __pfx_show_hw_stats+0x10/0x10 [ib_core]
[42021.988482]  [<ffffffffc077564e>] ? hw_stat_device_show+0x1e/0x40 [ib_core]
[42021.995438]  [<ffffffff86ac7f8e>] dev_attr_show+0x1e/0x50
[42022.000803]  [<ffffffff86a3eeb1>] sysfs_kf_seq_show+0x81/0xe0
[42022.006508]  [<ffffffff86a11134>] seq_read_iter+0xf4/0x410
[42022.011954]  [<ffffffff869f4b2e>] vfs_read+0x16e/0x2f0
[42022.017058]  [<ffffffff869f50ee>] ksys_read+0x6e/0xe0
[42022.022073]  [<ffffffff8766f1ca>] do_syscall_64+0x6a/0xa0
[42022.027441]  [<ffffffff8780013b>] entry_SYSCALL_64_after_hwframe+0x78/0xe2

The problem can be reproduced using the following steps:
  ip netns add foo
  ip netns exec foo bash
  cat /sys/class/infiniband/mlx4_0/hw_counters/*

The panic occurs because of casting the device pointer into an
ib_device pointer using container_of() in hw_stat_device_show() is
wrong and leads to a memory corruption.

However the real problem is that hw counters should never been exposed
outside of the non-init net namespace.

Fix this by saving the index of the corresponding attribute group
(it might be 1 or 2 depending on the presence of driver-specific
attributes) and zeroing the pointer to hw_counters group for compat
devices during the initialization.

With this fix applied hw_counters are not available in a non-init
net namespace:
  find /sys/class/infiniband/mlx4_0/ -name hw_counters
    /sys/class/infiniband/mlx4_0/ports/1/hw_counters
    /sys/class/infiniband/mlx4_0/ports/2/hw_counters
    /sys/class/infiniband/mlx4_0/hw_counters

  ip netns add foo
  ip netns exec foo bash
  find /sys/class/infiniband/mlx4_0/ -name hw_counters

Fixes: 467f432a521a ("RDMA/core: Split port and device counter sysfs attributes")
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Maher Sanalla <msanalla@nvidia.com>
Cc: Parav Pandit <parav@mellanox.com>
Cc: linux-rdma@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/infiniband/core/device.c | 9 +++++++++
 drivers/infiniband/core/sysfs.c  | 1 +
 include/rdma/ib_verbs.h          | 1 +
 3 files changed, 11 insertions(+)

diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 0ded91f056f3..8feb22089cbb 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -528,6 +528,8 @@ static struct class ib_class = {
 static void rdma_init_coredev(struct ib_core_device *coredev,
 			      struct ib_device *dev, struct net *net)
 {
+	bool is_full_dev = &dev->coredev == coredev;
+
 	/* This BUILD_BUG_ON is intended to catch layout change
 	 * of union of ib_core_device and device.
 	 * dev must be the first element as ib_core and providers
@@ -539,6 +541,13 @@ static void rdma_init_coredev(struct ib_core_device *coredev,
 
 	coredev->dev.class = &ib_class;
 	coredev->dev.groups = dev->groups;
+
+	/*
+	 * Don't expose hw counters outside of the init namespace.
+	 */
+	if (!is_full_dev && dev->hw_stats_attr_index)
+		coredev->dev.groups[dev->hw_stats_attr_index] = NULL;
+
 	device_initialize(&coredev->dev);
 	coredev->owner = dev;
 	INIT_LIST_HEAD(&coredev->port_list);
diff --git a/drivers/infiniband/core/sysfs.c b/drivers/infiniband/core/sysfs.c
index 7491328ca5e6..0ed862b38b44 100644
--- a/drivers/infiniband/core/sysfs.c
+++ b/drivers/infiniband/core/sysfs.c
@@ -976,6 +976,7 @@ int ib_setup_device_attrs(struct ib_device *ibdev)
 	for (i = 0; i != ARRAY_SIZE(ibdev->groups); i++)
 		if (!ibdev->groups[i]) {
 			ibdev->groups[i] = &data->group;
+			ibdev->hw_stats_attr_index = i;
 			return 0;
 		}
 	WARN(true, "struct ib_device->groups is too small");
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index b59bf30de430..a5761038935d 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2767,6 +2767,7 @@ struct ib_device {
 	 * It is a NULL terminated array.
 	 */
 	const struct attribute_group	*groups[4];
+	u8				hw_stats_attr_index;
 
 	u64			     uverbs_cmd_mask;
 
-- 
2.48.1.711.g2feabab25a-goog

RE: [PATCH] RDMA/core: don't expose hw_counters outside of init net namespace

[Parav Pandit]

> From: Roman Gushchin <roman.gushchin@linux.dev>
> Sent: Thursday, February 27, 2025 12:32 AM
> 
> Commit 5fd8529350f0 ("RDMA/core: fix a NULL-pointer dereference in
> hw_stat_device_show()") accidentally almost exposed hw counters to non-init
> net namespaces. It didn't expose them fully, as an attempt to read any of
> those counters leads to a crash like this one:
> 
It is not the commit 5fd8529350f0.
You just want to say cited commit accidentally..

> [42021.807566] BUG: kernel NULL pointer dereference, address:
> 0000000000000028 [42021.814463] #PF: supervisor read access in kernel
> mode [42021.819549] #PF: error_code(0x0000) - not-present page
> [42021.824636] PGD 0 P4D 0 [42021.827145] Oops: 0000 [#1] SMP PTI
> [42021.830598] CPU: 82 PID: 2843922 Comm: switchto-defaul Kdump: loaded
> Tainted: G S      W I        XXX
> [42021.841697] Hardware name: XXX
> [42021.849619] RIP: 0010:hw_stat_device_show+0x1e/0x40 [ib_core]
> [42021.855362] Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f
> 44 00 00 49 89 d0 4c 8b 5e 20 48 8b 8f b8 04 00 00 48 81 c7 f0 fa ff ff <48> 8b
> 41 28 48 29 ce 48 83 c6 d0 48 c1 ee 04 69 d6 ab aa aa aa 48 [42021.873931]
> RSP: 0018:ffff97fe90f03da0 EFLAGS: 00010287 [42021.879108] RAX:
> ffff9406988a8c60 RBX: ffff940e1072d438 RCX: 0000000000000000
> [42021.886169] RDX: ffff94085f1aa000 RSI: ffff93c6cbbdbcb0 RDI:
> ffff940c7517aef0 [42021.893230] RBP: ffff97fe90f03e70 R08:
> ffff94085f1aa000 R09: 0000000000000000 [42021.900294] R10:
> ffff94085f1aa000 R11: ffffffffc0775680 R12: ffffffff87ca2530 [42021.907355]
> R13: ffff940651602840 R14: ffff93c6cbbdbcb0 R15: ffff94085f1aa000
> [42021.914418] FS:  00007fda1a3b9700(0000) GS:ffff94453fb80000(0000)
> knlGS:0000000000000000 [42021.922423] CS:  0010 DS: 0000 ES: 0000 CR0:
> 0000000080050033 [42021.928130] CR2: 0000000000000028 CR3:
> 00000042dcfb8003 CR4: 00000000003726f0 [42021.935194] DR0:
> 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [42021.942257] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
> 0000000000000400 [42021.949324] Call Trace:
> [42021.951756]  <TASK>
> [42021.953842]  [<ffffffff86c58674>] ? show_regs+0x64/0x70 [42021.959030]
> [<ffffffff86c58468>] ? __die+0x78/0xc0 [42021.963874]  [<ffffffff86c9ef75>] ?
> page_fault_oops+0x2b5/0x3b0 [42021.969749]  [<ffffffff87674b92>] ?
> exc_page_fault+0x1a2/0x3c0 [42021.975549]  [<ffffffff87801326>] ?
> asm_exc_page_fault+0x26/0x30 [42021.981517]  [<ffffffffc0775680>] ?
> __pfx_show_hw_stats+0x10/0x10 [ib_core] [42021.988482]
> [<ffffffffc077564e>] ? hw_stat_device_show+0x1e/0x40 [ib_core]
> [42021.995438]  [<ffffffff86ac7f8e>] dev_attr_show+0x1e/0x50
> [42022.000803]  [<ffffffff86a3eeb1>] sysfs_kf_seq_show+0x81/0xe0
> [42022.006508]  [<ffffffff86a11134>] seq_read_iter+0xf4/0x410
> [42022.011954]  [<ffffffff869f4b2e>] vfs_read+0x16e/0x2f0 [42022.017058]
> [<ffffffff869f50ee>] ksys_read+0x6e/0xe0 [42022.022073]  [<ffffffff8766f1ca>]
> do_syscall_64+0x6a/0xa0 [42022.027441]  [<ffffffff8780013b>]
> entry_SYSCALL_64_after_hwframe+0x78/0xe2
> 
> The problem can be reproduced using the following steps:
>   ip netns add foo
>   ip netns exec foo bash
>   cat /sys/class/infiniband/mlx4_0/hw_counters/*
> 
> The panic occurs because of casting the device pointer into an ib_device
> pointer using container_of() in hw_stat_device_show() is wrong and leads to a
> memory corruption.
> 
> However the real problem is that hw counters should never been exposed
> outside of the non-init net namespace.
> 
> Fix this by saving the index of the corresponding attribute group (it might be 1
> or 2 depending on the presence of driver-specific
> attributes) and zeroing the pointer to hw_counters group for compat devices
> during the initialization.
> 
> With this fix applied hw_counters are not available in a non-init net
> namespace:
>   find /sys/class/infiniband/mlx4_0/ -name hw_counters
>     /sys/class/infiniband/mlx4_0/ports/1/hw_counters
>     /sys/class/infiniband/mlx4_0/ports/2/hw_counters
>     /sys/class/infiniband/mlx4_0/hw_counters
> 
>   ip netns add foo
>   ip netns exec foo bash
>   find /sys/class/infiniband/mlx4_0/ -name hw_counters
> 
> Fixes: 467f432a521a ("RDMA/core: Split port and device counter sysfs
> attributes")
> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
> Cc: Jason Gunthorpe <jgg@ziepe.ca>
> Cc: Leon Romanovsky <leon@kernel.org>
> Cc: Maher Sanalla <msanalla@nvidia.com>
> Cc: Parav Pandit <parav@mellanox.com>
> Cc: linux-rdma@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> ---
>  drivers/infiniband/core/device.c | 9 +++++++++
> drivers/infiniband/core/sysfs.c  | 1 +
>  include/rdma/ib_verbs.h          | 1 +
>  3 files changed, 11 insertions(+)
> 
> diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
> index 0ded91f056f3..8feb22089cbb 100644
> --- a/drivers/infiniband/core/device.c
> +++ b/drivers/infiniband/core/device.c
> @@ -528,6 +528,8 @@ static struct class ib_class = {  static void
> rdma_init_coredev(struct ib_core_device *coredev,
>  			      struct ib_device *dev, struct net *net)  {
> +	bool is_full_dev = &dev->coredev == coredev;
> +
>  	/* This BUILD_BUG_ON is intended to catch layout change
>  	 * of union of ib_core_device and device.
>  	 * dev must be the first element as ib_core and providers @@ -539,6
> +541,13 @@ static void rdma_init_coredev(struct ib_core_device *coredev,
> 
>  	coredev->dev.class = &ib_class;
>  	coredev->dev.groups = dev->groups;
> +
> +	/*
> +	 * Don't expose hw counters outside of the init namespace.
> +	 */
> +	if (!is_full_dev && dev->hw_stats_attr_index)
> +		coredev->dev.groups[dev->hw_stats_attr_index] = NULL;
> +
>  	device_initialize(&coredev->dev);
>  	coredev->owner = dev;
>  	INIT_LIST_HEAD(&coredev->port_list);
> diff --git a/drivers/infiniband/core/sysfs.c b/drivers/infiniband/core/sysfs.c
> index 7491328ca5e6..0ed862b38b44 100644
> --- a/drivers/infiniband/core/sysfs.c
> +++ b/drivers/infiniband/core/sysfs.c
> @@ -976,6 +976,7 @@ int ib_setup_device_attrs(struct ib_device *ibdev)
>  	for (i = 0; i != ARRAY_SIZE(ibdev->groups); i++)
>  		if (!ibdev->groups[i]) {
>  			ibdev->groups[i] = &data->group;
> +			ibdev->hw_stats_attr_index = i;
>  			return 0;
>  		}
>  	WARN(true, "struct ib_device->groups is too small"); diff --git
> a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index
> b59bf30de430..a5761038935d 100644
> --- a/include/rdma/ib_verbs.h
> +++ b/include/rdma/ib_verbs.h
> @@ -2767,6 +2767,7 @@ struct ib_device {
>  	 * It is a NULL terminated array.
>  	 */
>  	const struct attribute_group	*groups[4];
> +	u8				hw_stats_attr_index;
> 
>  	u64			     uverbs_cmd_mask;
> 
> --
> 2.48.1.711.g2feabab25a-goog

With above suggested small commit log correction, 
Reviewed-by: Parav Pandit <parav@nvidia.com>

Re: [PATCH] RDMA/core: don't expose hw_counters outside of init net namespace

[Roman Gushchin]

On Thu, Feb 27, 2025 at 05:22:59AM +0000, Parav Pandit wrote:
> 
> > From: Roman Gushchin <roman.gushchin@linux.dev>
> > Sent: Thursday, February 27, 2025 12:32 AM
> > 
> > Commit 5fd8529350f0 ("RDMA/core: fix a NULL-pointer dereference in
> > hw_stat_device_show()") accidentally almost exposed hw counters to non-init
> > net namespaces. It didn't expose them fully, as an attempt to read any of
> > those counters leads to a crash like this one:
> > 
> It is not the commit 5fd8529350f0.
> You just want to say cited commit accidentally..

Right, it's a typo, it had to be 467f432a521a ("RDMA/core: Split port
and device counter sysfs attributes").

> >  	WARN(true, "struct ib_device->groups is too small"); diff --git
> > a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index
> > b59bf30de430..a5761038935d 100644
> > --- a/include/rdma/ib_verbs.h
> > +++ b/include/rdma/ib_verbs.h
> > @@ -2767,6 +2767,7 @@ struct ib_device {
> >  	 * It is a NULL terminated array.
> >  	 */
> >  	const struct attribute_group	*groups[4];
> > +	u8				hw_stats_attr_index;
> > 
> >  	u64			     uverbs_cmd_mask;
> > 
> > --
> > 2.48.1.711.g2feabab25a-goog
> 
> With above suggested small commit log correction, 
> Reviewed-by: Parav Pandit <parav@nvidia.com>

Thank you!

[PATCH] RDMA/core: don't expose hw_counters outside of init net namespace

[Roman Gushchin]

Commit 467f432a521a ("RDMA/core: Split port and device counter sysfs
attributes") accidentally almost exposed hw counters to non-init net
namespaces. It didn't expose them fully, as an attempt to read any of
those counters leads to a crash like this one:

[42021.807566] BUG: kernel NULL pointer dereference, address: 0000000000000028
[42021.814463] #PF: supervisor read access in kernel mode
[42021.819549] #PF: error_code(0x0000) - not-present page
[42021.824636] PGD 0 P4D 0
[42021.827145] Oops: 0000 [#1] SMP PTI
[42021.830598] CPU: 82 PID: 2843922 Comm: switchto-defaul Kdump: loaded Tainted: G S      W I        XXX
[42021.841697] Hardware name: XXX
[42021.849619] RIP: 0010:hw_stat_device_show+0x1e/0x40 [ib_core]
[42021.855362] Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 49 89 d0 4c 8b 5e 20 48 8b 8f b8 04 00 00 48 81 c7 f0 fa ff ff <48> 8b 41 28 48 29 ce 48 83 c6 d0 48 c1 ee 04 69 d6 ab aa aa aa 48
[42021.873931] RSP: 0018:ffff97fe90f03da0 EFLAGS: 00010287
[42021.879108] RAX: ffff9406988a8c60 RBX: ffff940e1072d438 RCX: 0000000000000000
[42021.886169] RDX: ffff94085f1aa000 RSI: ffff93c6cbbdbcb0 RDI: ffff940c7517aef0
[42021.893230] RBP: ffff97fe90f03e70 R08: ffff94085f1aa000 R09: 0000000000000000
[42021.900294] R10: ffff94085f1aa000 R11: ffffffffc0775680 R12: ffffffff87ca2530
[42021.907355] R13: ffff940651602840 R14: ffff93c6cbbdbcb0 R15: ffff94085f1aa000
[42021.914418] FS:  00007fda1a3b9700(0000) GS:ffff94453fb80000(0000) knlGS:0000000000000000
[42021.922423] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[42021.928130] CR2: 0000000000000028 CR3: 00000042dcfb8003 CR4: 00000000003726f0
[42021.935194] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[42021.942257] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[42021.949324] Call Trace:
[42021.951756]  <TASK>
[42021.953842]  [<ffffffff86c58674>] ? show_regs+0x64/0x70
[42021.959030]  [<ffffffff86c58468>] ? __die+0x78/0xc0
[42021.963874]  [<ffffffff86c9ef75>] ? page_fault_oops+0x2b5/0x3b0
[42021.969749]  [<ffffffff87674b92>] ? exc_page_fault+0x1a2/0x3c0
[42021.975549]  [<ffffffff87801326>] ? asm_exc_page_fault+0x26/0x30
[42021.981517]  [<ffffffffc0775680>] ? __pfx_show_hw_stats+0x10/0x10 [ib_core]
[42021.988482]  [<ffffffffc077564e>] ? hw_stat_device_show+0x1e/0x40 [ib_core]
[42021.995438]  [<ffffffff86ac7f8e>] dev_attr_show+0x1e/0x50
[42022.000803]  [<ffffffff86a3eeb1>] sysfs_kf_seq_show+0x81/0xe0
[42022.006508]  [<ffffffff86a11134>] seq_read_iter+0xf4/0x410
[42022.011954]  [<ffffffff869f4b2e>] vfs_read+0x16e/0x2f0
[42022.017058]  [<ffffffff869f50ee>] ksys_read+0x6e/0xe0
[42022.022073]  [<ffffffff8766f1ca>] do_syscall_64+0x6a/0xa0
[42022.027441]  [<ffffffff8780013b>] entry_SYSCALL_64_after_hwframe+0x78/0xe2

The problem can be reproduced using the following steps:
  ip netns add foo
  ip netns exec foo bash
  cat /sys/class/infiniband/mlx4_0/hw_counters/*

The panic occurs because of casting the device pointer into an
ib_device pointer using container_of() in hw_stat_device_show() is
wrong and leads to a memory corruption.

However the real problem is that hw counters should never been exposed
outside of the non-init net namespace.

Fix this by saving the index of the corresponding attribute group
(it might be 1 or 2 depending on the presence of driver-specific
attributes) and zeroing the pointer to hw_counters group for compat
devices during the initialization.

With this fix applied hw_counters are not available in a non-init
net namespace:
  find /sys/class/infiniband/mlx4_0/ -name hw_counters
    /sys/class/infiniband/mlx4_0/ports/1/hw_counters
    /sys/class/infiniband/mlx4_0/ports/2/hw_counters
    /sys/class/infiniband/mlx4_0/hw_counters

  ip netns add foo
  ip netns exec foo bash
  find /sys/class/infiniband/mlx4_0/ -name hw_counters

Fixes: 467f432a521a ("RDMA/core: Split port and device counter sysfs attributes")
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Parav Pandit <parav@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Maher Sanalla <msanalla@nvidia.com>
Cc: linux-rdma@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/infiniband/core/device.c | 9 +++++++++
 drivers/infiniband/core/sysfs.c  | 1 +
 include/rdma/ib_verbs.h          | 1 +
 3 files changed, 11 insertions(+)

diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 0ded91f056f3..8feb22089cbb 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -528,6 +528,8 @@ static struct class ib_class = {
 static void rdma_init_coredev(struct ib_core_device *coredev,
 			      struct ib_device *dev, struct net *net)
 {
+	bool is_full_dev = &dev->coredev == coredev;
+
 	/* This BUILD_BUG_ON is intended to catch layout change
 	 * of union of ib_core_device and device.
 	 * dev must be the first element as ib_core and providers
@@ -539,6 +541,13 @@ static void rdma_init_coredev(struct ib_core_device *coredev,
 
 	coredev->dev.class = &ib_class;
 	coredev->dev.groups = dev->groups;
+
+	/*
+	 * Don't expose hw counters outside of the init namespace.
+	 */
+	if (!is_full_dev && dev->hw_stats_attr_index)
+		coredev->dev.groups[dev->hw_stats_attr_index] = NULL;
+
 	device_initialize(&coredev->dev);
 	coredev->owner = dev;
 	INIT_LIST_HEAD(&coredev->port_list);
diff --git a/drivers/infiniband/core/sysfs.c b/drivers/infiniband/core/sysfs.c
index 7491328ca5e6..0ed862b38b44 100644
--- a/drivers/infiniband/core/sysfs.c
+++ b/drivers/infiniband/core/sysfs.c
@@ -976,6 +976,7 @@ int ib_setup_device_attrs(struct ib_device *ibdev)
 	for (i = 0; i != ARRAY_SIZE(ibdev->groups); i++)
 		if (!ibdev->groups[i]) {
 			ibdev->groups[i] = &data->group;
+			ibdev->hw_stats_attr_index = i;
 			return 0;
 		}
 	WARN(true, "struct ib_device->groups is too small");
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index b59bf30de430..a5761038935d 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2767,6 +2767,7 @@ struct ib_device {
 	 * It is a NULL terminated array.
 	 */
 	const struct attribute_group	*groups[4];
+	u8				hw_stats_attr_index;
 
 	u64			     uverbs_cmd_mask;
 
-- 
2.48.1.711.g2feabab25a-goog

Re: [PATCH] RDMA/core: don't expose hw_counters outside of init net namespace

[Leon Romanovsky]

On Thu, 27 Feb 2025 16:54:20 +0000, Roman Gushchin wrote:
> Commit 467f432a521a ("RDMA/core: Split port and device counter sysfs
> attributes") accidentally almost exposed hw counters to non-init net
> namespaces. It didn't expose them fully, as an attempt to read any of
> those counters leads to a crash like this one:
> 
> [42021.807566] BUG: kernel NULL pointer dereference, address: 0000000000000028
> [42021.814463] #PF: supervisor read access in kernel mode
> [42021.819549] #PF: error_code(0x0000) - not-present page
> [42021.824636] PGD 0 P4D 0
> [42021.827145] Oops: 0000 [#1] SMP PTI
> [42021.830598] CPU: 82 PID: 2843922 Comm: switchto-defaul Kdump: loaded Tainted: G S      W I        XXX
> [42021.841697] Hardware name: XXX
> [42021.849619] RIP: 0010:hw_stat_device_show+0x1e/0x40 [ib_core]
> [42021.855362] Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 49 89 d0 4c 8b 5e 20 48 8b 8f b8 04 00 00 48 81 c7 f0 fa ff ff <48> 8b 41 28 48 29 ce 48 83 c6 d0 48 c1 ee 04 69 d6 ab aa aa aa 48
> [42021.873931] RSP: 0018:ffff97fe90f03da0 EFLAGS: 00010287
> [42021.879108] RAX: ffff9406988a8c60 RBX: ffff940e1072d438 RCX: 0000000000000000
> [42021.886169] RDX: ffff94085f1aa000 RSI: ffff93c6cbbdbcb0 RDI: ffff940c7517aef0
> [42021.893230] RBP: ffff97fe90f03e70 R08: ffff94085f1aa000 R09: 0000000000000000
> [42021.900294] R10: ffff94085f1aa000 R11: ffffffffc0775680 R12: ffffffff87ca2530
> [42021.907355] R13: ffff940651602840 R14: ffff93c6cbbdbcb0 R15: ffff94085f1aa000
> [42021.914418] FS:  00007fda1a3b9700(0000) GS:ffff94453fb80000(0000) knlGS:0000000000000000
> [42021.922423] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [42021.928130] CR2: 0000000000000028 CR3: 00000042dcfb8003 CR4: 00000000003726f0
> [42021.935194] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [42021.942257] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> [42021.949324] Call Trace:
> [42021.951756]  <TASK>
> [42021.953842]  [<ffffffff86c58674>] ? show_regs+0x64/0x70
> [42021.959030]  [<ffffffff86c58468>] ? __die+0x78/0xc0
> [42021.963874]  [<ffffffff86c9ef75>] ? page_fault_oops+0x2b5/0x3b0
> [42021.969749]  [<ffffffff87674b92>] ? exc_page_fault+0x1a2/0x3c0
> [42021.975549]  [<ffffffff87801326>] ? asm_exc_page_fault+0x26/0x30
> [42021.981517]  [<ffffffffc0775680>] ? __pfx_show_hw_stats+0x10/0x10 [ib_core]
> [42021.988482]  [<ffffffffc077564e>] ? hw_stat_device_show+0x1e/0x40 [ib_core]
> [42021.995438]  [<ffffffff86ac7f8e>] dev_attr_show+0x1e/0x50
> [42022.000803]  [<ffffffff86a3eeb1>] sysfs_kf_seq_show+0x81/0xe0
> [42022.006508]  [<ffffffff86a11134>] seq_read_iter+0xf4/0x410
> [42022.011954]  [<ffffffff869f4b2e>] vfs_read+0x16e/0x2f0
> [42022.017058]  [<ffffffff869f50ee>] ksys_read+0x6e/0xe0
> [42022.022073]  [<ffffffff8766f1ca>] do_syscall_64+0x6a/0xa0
> [42022.027441]  [<ffffffff8780013b>] entry_SYSCALL_64_after_hwframe+0x78/0xe2
> 
> [...]

Applied, thanks!

[1/1] RDMA/core: don't expose hw_counters outside of init net namespace
      https://git.kernel.org/rdma/rdma/c/57b9340c0728b0

Best regards,
-- 
Leon Romanovsky <leon@kernel.org>