> -----Original Message-----
> From: Michael S. Tsirkin <[email protected]>
> Sent: Friday, January 2, 2026 4:58 PM
> To: Shiva Shankar Kommula <[email protected]>
> Cc: [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected]; linux-
> [email protected]; Jerin Jacob <[email protected]>; Nithin Kumar
> Dabilpuram <[email protected]>; Srujana Challa
> <[email protected]>
> Subject: [EXTERNAL] Re: [PATCH net] virtio_net: fix device mismatch in
> devm_kzalloc/devm_kfree
>
> On Fri, Jan 02, 2026 at 03: 49: 00PM +0530, Kommula Shiva Shankar wrote: >
> Initial rss_hdr allocation uses virtio_device->device, > but
> virtnet_set_queues()
> frees using net_device->device. > This device mismatch causing below devres
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> On Fri, Jan 02, 2026 at 03:49:00PM +0530, Kommula Shiva Shankar wrote:
> > Initial rss_hdr allocation uses virtio_device->device, but
> > virtnet_set_queues() frees using net_device->device.
> > This device mismatch causing below devres warning
> >
> > [ 3788.514041] ------------[ cut here ]------------ [ 3788.514044]
> > WARNING: drivers/base/devres.c:1095 at devm_kfree+0x84/0x98, CPU#16:
> > vdpa/1463 [ 3788.514054] Modules linked in: octep_vdpa virtio_net
> virtio_vdpa [last unloaded: virtio_vdpa]
> > [ 3788.514064] CPU: 16 UID: 0 PID: 1463 Comm: vdpa Tainted: G W
> 6.18.0 #10 PREEMPT
> > [ 3788.514067] Tainted: [W]=WARN
> > [ 3788.514069] Hardware name: Marvell CN106XX board (DT) [
> > 3788.514071] pstate: 63400009 (nZCv daif +PAN -UAO +TCO +DIT -SSBS
> > BTYPE=--) [ 3788.514074] pc : devm_kfree+0x84/0x98 [ 3788.514076] lr :
> > devm_kfree+0x54/0x98 [ 3788.514079] sp : ffff800084e2f220 [
> > 3788.514080] x29: ffff800084e2f220 x28: ffff0003b2366000 x27:
> > 000000000000003f [ 3788.514085] x26: 000000000000003f x25:
> > ffff000106f17c10 x24: 0000000000000080 [ 3788.514089] x23:
> > ffff00045bb8ab08 x22: ffff00045bb8a000 x21: 0000000000000018 [
> > 3788.514093] x20: ffff0004355c3080 x19: ffff00045bb8aa00 x18:
> > 0000000000080000 [ 3788.514098] x17: 0000000000000040 x16:
> > 000000000000001f x15: 000000000007ffff [ 3788.514102] x14:
> > 0000000000000488 x13: 0000000000000005 x12: 00000000000fffff [
> > 3788.514106] x11: ffffffffffffffff x10: 0000000000000005 x9 :
> > ffff800080c8c05c [ 3788.514110] x8 : ffff800084e2eeb8 x7 :
> > 0000000000000000 x6 : 000000000000003f [ 3788.514115] x5 :
> ffff8000831bafe0 x4 : ffff800080c8b010 x3 : ffff0004355c3080 [
> 3788.514119] x2 : ffff0004355c3080 x1 : 0000000000000000 x0 :
> 0000000000000000 [ 3788.514123] Call trace:
> > [ 3788.514125] devm_kfree+0x84/0x98 (P) [ 3788.514129]
> > virtnet_set_queues+0x134/0x2e8 [virtio_net] [ 3788.514135]
> > virtnet_probe+0x9c0/0xe00 [virtio_net] [ 3788.514139]
> > virtio_dev_probe+0x1e0/0x338 [ 3788.514144] really_probe+0xc8/0x3a0 [
> > 3788.514149] __driver_probe_device+0x84/0x170 [ 3788.514152]
> > driver_probe_device+0x44/0x120 [ 3788.514155]
> > __device_attach_driver+0xc4/0x168 [ 3788.514158]
> > bus_for_each_drv+0x8c/0xf0 [ 3788.514161] __device_attach+0xa4/0x1c0
> > [ 3788.514164] device_initial_probe+0x1c/0x30 [ 3788.514168]
> > bus_probe_device+0xb4/0xc0 [ 3788.514170] device_add+0x614/0x828 [
> > 3788.514173] register_virtio_device+0x214/0x258
> > [ 3788.514175] virtio_vdpa_probe+0xa0/0x110 [virtio_vdpa] [
> > 3788.514179] vdpa_dev_probe+0xa8/0xd8 [ 3788.514183]
> > really_probe+0xc8/0x3a0 [ 3788.514186]
> > __driver_probe_device+0x84/0x170 [ 3788.514189]
> > driver_probe_device+0x44/0x120 [ 3788.514192]
> > __device_attach_driver+0xc4/0x168 [ 3788.514195]
> > bus_for_each_drv+0x8c/0xf0 [ 3788.514197] __device_attach+0xa4/0x1c0
> > [ 3788.514200] device_initial_probe+0x1c/0x30 [ 3788.514203]
> > bus_probe_device+0xb4/0xc0 [ 3788.514206] device_add+0x614/0x828 [
> > 3788.514209] _vdpa_register_device+0x58/0x88 [ 3788.514211]
> > octep_vdpa_dev_add+0x104/0x228 [octep_vdpa] [ 3788.514215]
> > vdpa_nl_cmd_dev_add_set_doit+0x2d0/0x3c0
> > [ 3788.514218] genl_family_rcv_msg_doit+0xe4/0x158
> > [ 3788.514222] genl_rcv_msg+0x218/0x298 [ 3788.514225]
> > netlink_rcv_skb+0x64/0x138 [ 3788.514229] genl_rcv+0x40/0x60 [
> > 3788.514233] netlink_unicast+0x32c/0x3b0 [ 3788.514237]
> > netlink_sendmsg+0x170/0x3b8 [ 3788.514241]
> __sys_sendto+0x12c/0x1c0 [
> > 3788.514246] __arm64_sys_sendto+0x30/0x48 [ 3788.514249]
> > invoke_syscall.constprop.0+0x58/0xf8
> > [ 3788.514255] do_el0_svc+0x48/0xd0
> > [ 3788.514259] el0_svc+0x48/0x210
> > [ 3788.514264] el0t_64_sync_handler+0xa0/0xe8 [ 3788.514268]
> > el0t_64_sync+0x198/0x1a0 [ 3788.514271] ---[ end trace
> > 0000000000000000 ]---
> >
> > Fix by using virtio_device->device consistently for allocation and
> > deallocation
> >
> > Fixes: 4944be2f5ad8c ("virtio_net: Allocate rss_hdr with devres")
> > Signed-off-by: Kommula Shiva Shankar <[email protected]>
>
> And not just a warning, it can be a memleak/double free, right?
Agreed. Memory leak occurs in this scenario.
>
> Acked-by: Michael S. Tsirkin <[email protected]>
>
> > ---
> > drivers/net/virtio_net.c | 6 +++---
> > 1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index
> > 1bb3aeca66c6..22d894101c01 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> > @@ -3791,7 +3791,7 @@ static int virtnet_set_queues(struct virtnet_info
> *vi, u16 queue_pairs)
> > if (vi->has_rss && !netif_is_rxfh_configured(dev)) {
> > old_rss_hdr = vi->rss_hdr;
> > old_rss_trailer = vi->rss_trailer;
> > - vi->rss_hdr = devm_kzalloc(&dev->dev,
> virtnet_rss_hdr_size(vi), GFP_KERNEL);
> > + vi->rss_hdr = devm_kzalloc(&vi->vdev->dev,
> > +virtnet_rss_hdr_size(vi), GFP_KERNEL);
> > if (!vi->rss_hdr) {
> > vi->rss_hdr = old_rss_hdr;
> > return -ENOMEM;
> > @@ -3802,7 +3802,7 @@ static int virtnet_set_queues(struct
> > virtnet_info *vi, u16 queue_pairs)
> >
> > if (!virtnet_commit_rss_command(vi)) {
> > /* restore ctrl_rss if commit_rss_command failed */
> > - devm_kfree(&dev->dev, vi->rss_hdr);
> > + devm_kfree(&vi->vdev->dev, vi->rss_hdr);
> > vi->rss_hdr = old_rss_hdr;
> > vi->rss_trailer = old_rss_trailer;
> >
> > @@ -3810,7 +3810,7 @@ static int virtnet_set_queues(struct virtnet_info
> *vi, u16 queue_pairs)
> > queue_pairs);
> > return -EINVAL;
> > }
> > - devm_kfree(&dev->dev, old_rss_hdr);
> > + devm_kfree(&vi->vdev->dev, old_rss_hdr);
> > goto succ;
> > }
> >
> > --
> > 2.48.1
