From: Greg Kroah-Hartman Date: Fri, 29 Apr 2022 08:42:56 +0000 (+0200) Subject: 4.19-stable patches X-Git-Tag: v4.19.241~17 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=d898e3c8716cc395d72a045af26ba2ad91f147d7;p=thirdparty%2Fkernel%2Fstable-queue.git 4.19-stable patches added patches: hamradio-defer-6pack-kfree-after-unregister_netdev.patch hamradio-remove-needs_free_netdev-to-avoid-uaf.patch --- diff --git a/queue-4.19/hamradio-defer-6pack-kfree-after-unregister_netdev.patch b/queue-4.19/hamradio-defer-6pack-kfree-after-unregister_netdev.patch new file mode 100644 index 00000000000..78478870851 --- /dev/null +++ b/queue-4.19/hamradio-defer-6pack-kfree-after-unregister_netdev.patch @@ -0,0 +1,51 @@ +From 0b9111922b1f399aba6ed1e1b8f2079c3da1aed8 Mon Sep 17 00:00:00 2001 +From: Lin Ma +Date: Mon, 8 Nov 2021 18:37:59 +0800 +Subject: hamradio: defer 6pack kfree after unregister_netdev + +From: Lin Ma + +commit 0b9111922b1f399aba6ed1e1b8f2079c3da1aed8 upstream. + +There is a possible race condition (use-after-free) like below + + (USE) | (FREE) + dev_queue_xmit | + __dev_queue_xmit | + __dev_xmit_skb | + sch_direct_xmit | ... + xmit_one | + netdev_start_xmit | tty_ldisc_kill + __netdev_start_xmit | 6pack_close + sp_xmit | kfree + sp_encaps | + | + +According to the patch "defer ax25 kfree after unregister_netdev", this +patch reorder the kfree after the unregister_netdev to avoid the possible +UAF as the unregister_netdev() is well synchronized and won't return if +there is a running routine. + +Signed-off-by: Lin Ma +Signed-off-by: David S. Miller +Signed-off-by: Ovidiu Panait +Signed-off-by: Greg Kroah-Hartman +--- + drivers/net/hamradio/6pack.c | 4 +++- + 1 file changed, 3 insertions(+), 1 deletion(-) + +--- a/drivers/net/hamradio/6pack.c ++++ b/drivers/net/hamradio/6pack.c +@@ -679,9 +679,11 @@ static void sixpack_close(struct tty_str + del_timer_sync(&sp->tx_t); + del_timer_sync(&sp->resync_t); + +- /* Free all 6pack frame buffers. */ ++ /* Free all 6pack frame buffers after unreg. */ + kfree(sp->rbuff); + kfree(sp->xbuff); ++ ++ free_netdev(sp->dev); + } + + /* Perform I/O control on an active 6pack channel. */ diff --git a/queue-4.19/hamradio-remove-needs_free_netdev-to-avoid-uaf.patch b/queue-4.19/hamradio-remove-needs_free_netdev-to-avoid-uaf.patch new file mode 100644 index 00000000000..cf07c60f73b --- /dev/null +++ b/queue-4.19/hamradio-remove-needs_free_netdev-to-avoid-uaf.patch @@ -0,0 +1,42 @@ +From 81b1d548d00bcd028303c4f3150fa753b9b8aa71 Mon Sep 17 00:00:00 2001 +From: Lin Ma +Date: Thu, 11 Nov 2021 22:14:02 +0800 +Subject: hamradio: remove needs_free_netdev to avoid UAF + +From: Lin Ma + +commit 81b1d548d00bcd028303c4f3150fa753b9b8aa71 upstream. + +The former patch "defer 6pack kfree after unregister_netdev" reorders +the kfree of two buffer after the unregister_netdev to prevent the race +condition. It also adds free_netdev() function in sixpack_close(), which +is a direct copy from the similar code in mkiss_close(). + +However, in sixpack driver, the flag needs_free_netdev is set to true in +sp_setup(), hence the unregister_netdev() will free the netdev +automatically. Therefore, as the sp is netdev_priv, use-after-free +occurs. + +This patch removes the needs_free_netdev = true and just let the +free_netdev to finish this deallocation task. + +Fixes: 0b9111922b1f ("hamradio: defer 6pack kfree after unregister_netdev") +Signed-off-by: Lin Ma +Link: https://lore.kernel.org/r/20211111141402.7551-1-linma@zju.edu.cn +Signed-off-by: Jakub Kicinski +Signed-off-by: Ovidiu Panait +Signed-off-by: Greg Kroah-Hartman +--- + drivers/net/hamradio/6pack.c | 1 - + 1 file changed, 1 deletion(-) + +--- a/drivers/net/hamradio/6pack.c ++++ b/drivers/net/hamradio/6pack.c +@@ -311,7 +311,6 @@ static void sp_setup(struct net_device * + { + /* Finish setting up the DEVICE info. */ + dev->netdev_ops = &sp_netdev_ops; +- dev->needs_free_netdev = true; + dev->mtu = SIXP_MTU; + dev->hard_header_len = AX25_MAX_HEADER_LEN; + dev->header_ops = &ax25_header_ops; diff --git a/queue-4.19/series b/queue-4.19/series index ee5dc79054b..3ba4da31d2a 100644 --- a/queue-4.19/series +++ b/queue-4.19/series @@ -1,2 +1,4 @@ media-vicodec-upon-release-call-m2m-release-before-freeing-ctrl-handler.patch floppy-disable-fdrawcmd-by-default.patch +hamradio-defer-6pack-kfree-after-unregister_netdev.patch +hamradio-remove-needs_free_netdev-to-avoid-uaf.patch