Hey all,
I recently used a testing program to test the 4.19 stable branch kernel and found that a crash occurred immediately. The test source code link is: https://github.com/Backmyheart/src0358/blob/master/vxlan_fdb_destroy.c
The test command is as follows: gcc vxlan_fdb_destroy.c -o vxlan_fdb_destroy -lpthread
According to its stack, upstream has relevant repair patch, the commit id is 7c31e54aeee517d1318dfc0bde9fa7de75893dc6.
May i ask if the 4.19 kernel will port this patch ?
On Tue, Apr 23, 2024 at 2:53 PM zhulei zhulei_szu@163.com wrote:
Hey all,
I recently used a testing program to test the 4.19 stable branch kernel and found that a crash occurred immediately. The test source code link is: https://github.com/Backmyheart/src0358/blob/master/vxlan_fdb_destroy.c
The test command is as follows: gcc vxlan_fdb_destroy.c -o vxlan_fdb_destroy -lpthread
According to its stack, upstream has relevant repair patch, the commit id is 7c31e54aeee517d1318dfc0bde9fa7de75893dc6.
May i ask if the 4.19 kernel will port this patch ?
Hi zhulei,
The commit 7c31e54aeee5 ("vxlan: do not destroy fdb if register_netdevice() is failed") was not backported to 4.19-stable tree. https://lore.kernel.org/stable/15641355392228@kroah.com/
So, you can request a backport. Please check the URL: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
Thanks a lot! Taehee Yoo
On Tue, Apr 23, 2024 at 01:52:40PM +0800, zhulei wrote:
Hey all,
I recently used a testing program to test the 4.19 stable branch kernel and found that a crash occurred immediately. The test source code link is: https://github.com/Backmyheart/src0358/blob/master/vxlan_fdb_destroy.c
The test command is as follows: gcc vxlan_fdb_destroy.c -o vxlan_fdb_destroy -lpthread
According to its stack, upstream has relevant repair patch, the commit id is 7c31e54aeee517d1318dfc0bde9fa7de75893dc6.
May i ask if the 4.19 kernel will port this patch ?
Have you tested to verify that it does work? If so, please provide the working patch because as-is, it does not apply to 4.19.y at all.
thansk,
greg k-h
By making the following changes and using our own 4.19 kernel verification, we can observe the output that passes the test in dmesg.
When using the 4.19 stable branch kernel for verification, the dmesg has no output, which looks more like the test program is not running. However, the code of vxlan.c is the same.
May i ask if the changes made to the maintainer are reasonable?
--- drivers/net/vxlan.c | 36 ++++++++++++++++++++++++++---------- 1 file changed, 26 insertions(+), 10 deletions(-)
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 704db80df38b..d3000c58c0f2 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -657,6 +657,14 @@ static struct vxlan_fdb *vxlan_fdb_alloc(struct vxlan_dev *vxlan, return f; }
+static void vxlan_fdb_insert(struct vxlan_dev *vxlan, const u8 *mac, + __be32 src_vni, struct vxlan_fdb *f) +{ + ++vxlan->addrcnt; + hlist_add_head_rcu(&f->hlist, + vxlan_fdb_head(vxlan, mac, src_vni)); +} + static int vxlan_fdb_create(struct vxlan_dev *vxlan, const u8 *mac, union vxlan_addr *ip, __u16 state, __be16 port, __be32 src_vni, @@ -682,10 +690,6 @@ static int vxlan_fdb_create(struct vxlan_dev *vxlan, return rc; }
- ++vxlan->addrcnt; - hlist_add_head_rcu(&f->hlist, - vxlan_fdb_head(vxlan, mac, src_vni)); - *fdb = f;
return 0; @@ -758,15 +762,15 @@ static int vxlan_fdb_update(struct vxlan_dev *vxlan, if (notify) { if (rd == NULL) rd = first_remote_rtnl(f); + vxlan_fdb_insert(vxlan, mac, src_vni, f); vxlan_fdb_notify(vxlan, f, rd, RTM_NEWNEIGH); }
return 0; }
-static void vxlan_fdb_free(struct rcu_head *head) +static void __vxlan_fdb_free(struct vxlan_fdb *f) { - struct vxlan_fdb *f = container_of(head, struct vxlan_fdb, rcu); struct vxlan_rdst *rd, *nd;
list_for_each_entry_safe(rd, nd, &f->remotes, list) { @@ -776,6 +780,13 @@ static void vxlan_fdb_free(struct rcu_head *head) kfree(f); }
+static void vxlan_fdb_free(struct rcu_head *head) +{ + struct vxlan_fdb *f = container_of(head, struct vxlan_fdb, rcu); + + __vxlan_fdb_free(f); +} + static void vxlan_fdb_destroy(struct vxlan_dev *vxlan, struct vxlan_fdb *f, bool do_notify) { @@ -3265,9 +3276,12 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev, if (err) goto errout;
- /* notify default fdb entry */ - if (f) + if (f) { + vxlan_fdb_insert(vxlan, all_zeros_mac, + vxlan->default_dst.remote_vni, f); + /* notify default fdb entry */ vxlan_fdb_notify(vxlan, f, first_remote_rtnl(f), RTM_NEWNEIGH); + }
list_add(&vxlan->next, &vn->vxlan_list); return 0; @@ -3278,9 +3292,11 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev, * destroy the entry by hand here. */ if (f) - vxlan_fdb_destroy(vxlan, f, false); - if (unregister) + __vxlan_fdb_free(f); + if (unregister) { + vxlan_fdb_destroy(vxlan, f, true); unregister_netdevice(dev); + } return err; }
On Tue, May 07, 2024 at 05:20:49PM +0800, zhulei wrote:
By making the following changes and using our own 4.19 kernel verification, we can observe the output that passes the test in dmesg.
When using the 4.19 stable branch kernel for verification, the dmesg has no output, which looks more like the test program is not running. However, the code of vxlan.c is the same.
May i ask if the changes made to the maintainer are reasonable?
Why is this only a 4.19.y thing? Why is this not also relevent for Linus's current tree?
thanks,
greg k-h
linux-stable-mirror@lists.linaro.org
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Greg KH -
Taehee Yoo -
zhulei -
zhulei