CVSS: -EPSS: 0%CPEs: 3EXPL: 0CVE-2021-47226 – x86/fpu: Invalidate FPU state after a failed XRSTOR from a user buffer
https://notcve.org/view.php?id=CVE-2021-47226
In the Linux kernel, the following vulnerability has been resolved: x86/fpu: Invalidate FPU state after a failed XRSTOR from a user buffer Both Intel and AMD consider it to be architecturally valid for XRSTOR to fail with #PF but nonetheless change the register state. The actual conditions under which this might occur are unclear [1], but it seems plausible that this might be triggered if one sibling thread unmaps a page and invalidates the shared TLB while another sibling thread is executing XRSTOR on the page in question. __fpu__restore_sig() can execute XRSTOR while the hardware registers are preserved on behalf of a different victim task (using the fpu_fpregs_owner_ctx mechanism), and, in theory, XRSTOR could fail but modify the registers. If this happens, then there is a window in which __fpu__restore_sig() could schedule out and the victim task could schedule back in without reloading its own FPU registers. This would result in part of the FPU state that __fpu__restore_sig() was attempting to load leaking into the victim task's user-visible state. Invalidate preserved FPU registers on XRSTOR failure to prevent this situation from corrupting any state. [1] Frequent readers of the errata lists might imagine "complex microarchitectural conditions". En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: x86/fpu: Invalida el estado de la FPU después de un XRSTOR fallido desde un búfer de usuario. Tanto Intel como AMD consideran que es arquitectónicamente válido que XRSTOR falle con #PF pero aun así cambie el estado del registro. . • https://git.kernel.org/stable/c/1d731e731c4cd7cbd3b1aa295f0932e7610da82f https://git.kernel.org/stable/c/a7748e021b9fb7739e3cb88449296539de0b6817 https://git.kernel.org/stable/c/002665dcba4bbec8c82f0aeb4bd3f44334ed2c14 https://git.kernel.org/stable/c/d8778e393afa421f1f117471144f8ce6deb6953a •
CVSS: -EPSS: 0%CPEs: 2EXPL: 0CVE-2021-47225 – mac80211: fix deadlock in AP/VLAN handling
https://notcve.org/view.php?id=CVE-2021-47225
In the Linux kernel, the following vulnerability has been resolved: mac80211: fix deadlock in AP/VLAN handling Syzbot reports that when you have AP_VLAN interfaces that are up and close the AP interface they belong to, we get a deadlock. No surprise - since we dev_close() them with the wiphy mutex held, which goes back into the netdev notifier in cfg80211 and tries to acquire the wiphy mutex there. To fix this, we need to do two things: 1) prevent changing iftype while AP_VLANs are up, we can't easily fix this case since cfg80211 already calls us with the wiphy mutex held, but change_interface() is relatively rare in drivers anyway, so changing iftype isn't used much (and userspace has to fall back to down/change/up anyway) 2) pull the dev_close() loop over VLANs out of the wiphy mutex section in the normal stop case En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mac80211: corrige el punto muerto en el manejo de AP/VLAN. Syzbot informa que cuando tienes interfaces AP_VLAN activas y cierras la interfaz AP a la que pertenecen, obtenemos un punto muerto. No es de extrañar, ya que los dev_close() los usamos con el mutex wiphy retenido, lo que regresa al notificador netdev en cfg80211 e intenta adquirir el mutex wiphy allí. Para solucionar esto, debemos hacer dos cosas: 1) evitar cambiar iftype mientras las AP_VLAN estén activas, no podemos solucionar fácilmente este caso ya que cfg80211 ya nos llama con el mutex wiphy retenido, pero change_interface() es relativamente raro en los controladores de todos modos , por lo que cambiar iftype no se usa mucho (y el espacio de usuario tiene que volver a bajar/cambiar/arriba de todos modos) 2) extraiga el bucle dev_close() sobre las VLAN de la sección wiphy mutex en el caso de detención normal • https://git.kernel.org/stable/c/a05829a7222e9d10c416dd2dbbf3929fe6646b89 https://git.kernel.org/stable/c/8043903fcb72f545c52e3ec74d6fd82ef79ce7c5 https://git.kernel.org/stable/c/d5befb224edbe53056c2c18999d630dafb4a08b9 •
CVSS: -EPSS: 0%CPEs: 4EXPL: 0CVE-2021-47224 – net: ll_temac: Make sure to free skb when it is completely used
https://notcve.org/view.php?id=CVE-2021-47224
In the Linux kernel, the following vulnerability has been resolved: net: ll_temac: Make sure to free skb when it is completely used With the skb pointer piggy-backed on the TX BD, we have a simple and efficient way to free the skb buffer when the frame has been transmitted. But in order to avoid freeing the skb while there are still fragments from the skb in use, we need to piggy-back on the TX BD of the skb, not the first. Without this, we are doing use-after-free on the DMA side, when the first BD of a multi TX BD packet is seen as completed in xmit_done, and the remaining BDs are still being processed. En el kernel de Linux se ha resuelto la siguiente vulnerabilidad: net:ll_temac: Asegúrate de liberar skb cuando esté completamente utilizado. Con el puntero skb acoplado en la BD TX, tenemos una forma sencilla y eficaz de liberar el buffer skb. cuando la trama ha sido transmitida. Pero para evitar liberar el skb mientras todavía hay fragmentos del skb en uso, debemos aprovechar el BD TX del skb, no el primero. Sin esto, estamos haciendo use after free en el lado DMA, cuando el primer BD de un paquete BD de transmisión múltiple se considera completado en xmit_done y los BD restantes todavía se están procesando. • https://git.kernel.org/stable/c/6d120ab4dc39a543c6b63361e1d0541c382900a3 https://git.kernel.org/stable/c/019ab7d044d0ebf97e1236bb8935b7809be92358 https://git.kernel.org/stable/c/e8afe05bd359ebe12a61dbdc94c06c00ea3e8d4b https://git.kernel.org/stable/c/6aa32217a9a446275440ee8724b1ecaf1838df47 •
CVSS: -EPSS: 0%CPEs: 6EXPL: 0CVE-2021-47223 – net: bridge: fix vlan tunnel dst null pointer dereference
https://notcve.org/view.php?id=CVE-2021-47223
In the Linux kernel, the following vulnerability has been resolved: net: bridge: fix vlan tunnel dst null pointer dereference This patch fixes a tunnel_dst null pointer dereference due to lockless access in the tunnel egress path. When deleting a vlan tunnel the tunnel_dst pointer is set to NULL without waiting a grace period (i.e. while it's still usable) and packets egressing are dereferencing it without checking. Use READ/WRITE_ONCE to annotate the lockless use of tunnel_id, use RCU for accessing tunnel_dst and make sure it is read only once and checked in the egress path. The dst is already properly RCU protected so we don't need to do anything fancy than to make sure tunnel_id and tunnel_dst are read only once and checked in the egress path. En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: net: bridge: corrige la desreferencia del puntero null del túnel vlan dst Este parche corrige una desreferencia del puntero null de Tunnel_dst debido al acceso sin bloqueo en la ruta de salida del túnel. • https://git.kernel.org/stable/c/11538d039ac6efcf4f1a6c536e1b87cd3668a9fd https://git.kernel.org/stable/c/ad7feefe7164892db424c45687472db803d87f79 https://git.kernel.org/stable/c/24a6e55f17aa123bc1fc54b7d3c410b41bc16530 https://git.kernel.org/stable/c/a2241e62f6b4a774d8a92048fdf59c45f6c2fe5c https://git.kernel.org/stable/c/fe0448a3fad365a747283a00a1d1ad5e8d6675b7 https://git.kernel.org/stable/c/abb02e05cb1c0a30dd873a29f33bc092067dc35d https://git.kernel.org/stable/c/58e2071742e38f29f051b709a5cca014ba51166f •
CVSS: -EPSS: 0%CPEs: 6EXPL: 0CVE-2021-47222 – net: bridge: fix vlan tunnel dst refcnt when egressing
https://notcve.org/view.php?id=CVE-2021-47222
In the Linux kernel, the following vulnerability has been resolved: net: bridge: fix vlan tunnel dst refcnt when egressing The egress tunnel code uses dst_clone() and directly sets the result which is wrong because the entry might have 0 refcnt or be already deleted, causing number of problems. It also triggers the WARN_ON() in dst_hold()[1] when a refcnt couldn't be taken. Fix it by using dst_hold_safe() and checking if a reference was actually taken before setting the dst. [1] dmesg WARN_ON log and following refcnt errors WARNING: CPU: 5 PID: 38 at include/net/dst.h:230 br_handle_egress_vlan_tunnel+0x10b/0x134 [bridge] Modules linked in: 8021q garp mrp bridge stp llc bonding ipv6 virtio_net CPU: 5 PID: 38 Comm: ksoftirqd/5 Kdump: loaded Tainted: G W 5.13.0-rc3+ #360 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014 RIP: 0010:br_handle_egress_vlan_tunnel+0x10b/0x134 [bridge] Code: e8 85 bc 01 e1 45 84 f6 74 90 45 31 f6 85 db 48 c7 c7 a0 02 19 a0 41 0f 94 c6 31 c9 31 d2 44 89 f6 e8 64 bc 01 e1 85 db 75 02 <0f> 0b 31 c9 31 d2 44 89 f6 48 c7 c7 70 02 19 a0 e8 4b bc 01 e1 49 RSP: 0018:ffff8881003d39e8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffffa01902a0 RBP: ffff8881040c6700 R08: 0000000000000000 R09: 0000000000000001 R10: 2ce93d0054fe0d00 R11: 54fe0d00000e0000 R12: ffff888109515000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000401 FS: 0000000000000000(0000) GS:ffff88822bf40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f42ba70f030 CR3: 0000000109926000 CR4: 00000000000006e0 Call Trace: br_handle_vlan+0xbc/0xca [bridge] __br_forward+0x23/0x164 [bridge] deliver_clone+0x41/0x48 [bridge] br_handle_frame_finish+0x36f/0x3aa [bridge] ? skb_dst+0x2e/0x38 [bridge] ? br_handle_ingress_vlan_tunnel+0x3e/0x1c8 [bridge] ? • https://git.kernel.org/stable/c/11538d039ac6efcf4f1a6c536e1b87cd3668a9fd https://git.kernel.org/stable/c/42020f7f37a90d24b9551f5f7eba3f7c7c102968 https://git.kernel.org/stable/c/84fc1c944e45ab317e2e70a0e7f76fa2a5e43b6e https://git.kernel.org/stable/c/79855be6445b6592bddb7bd7167083ec8cdbd73f https://git.kernel.org/stable/c/fc7fdd8c5c2ad2fe3e297698be9d4dbe4a4e0579 https://git.kernel.org/stable/c/25053a8404ba17ca48f5553d487afc1882e9f56c https://git.kernel.org/stable/c/cfc579f9d89af4ada58c69b03bcaa4887840f3b3 •