forked from TencentOS/TencentOS-kernel
3 Commits
| Author | SHA1 | Message | Date |
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Oleksij Rempel
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bcd6680381 |
can: skb: can_skb_set_owner(): fix ref counting if socket was closed before setting skb ownership
commit e940e0895a82c6fbaa259f2615eb52b57ee91a7e upstream. There are two ref count variables controlling the free()ing of a socket: - struct sock::sk_refcnt - which is changed by sock_hold()/sock_put() - struct sock::sk_wmem_alloc - which accounts the memory allocated by the skbs in the send path. In case there are still TX skbs on the fly and the socket() is closed, the struct sock::sk_refcnt reaches 0. In the TX-path the CAN stack clones an "echo" skb, calls sock_hold() on the original socket and references it. This produces the following back trace: | WARNING: CPU: 0 PID: 280 at lib/refcount.c:25 refcount_warn_saturate+0x114/0x134 | refcount_t: addition on 0; use-after-free. | Modules linked in: coda_vpu(E) v4l2_jpeg(E) videobuf2_vmalloc(E) imx_vdoa(E) | CPU: 0 PID: 280 Comm: test_can.sh Tainted: G E 5.11.0-04577-gf8ff6603c617 #203 | Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) | Backtrace: | [<80bafea4>] (dump_backtrace) from [<80bb0280>] (show_stack+0x20/0x24) r7:00000000 r6:600f0113 r5:00000000 r4:81441220 | [<80bb0260>] (show_stack) from [<80bb593c>] (dump_stack+0xa0/0xc8) | [<80bb589c>] (dump_stack) from [<8012b268>] (__warn+0xd4/0x114) r9:00000019 r8:80f4a8c2 r7:83e4150c r6:00000000 r5:00000009 r4:80528f90 | [<8012b194>] (__warn) from [<80bb09c4>] (warn_slowpath_fmt+0x88/0xc8) r9:83f26400 r8:80f4a8d1 r7:00000009 r6:80528f90 r5:00000019 r4:80f4a8c2 | [<80bb0940>] (warn_slowpath_fmt) from [<80528f90>] (refcount_warn_saturate+0x114/0x134) r8:00000000 r7:00000000 r6:82b44000 r5:834e5600 r4:83f4d540 | [<80528e7c>] (refcount_warn_saturate) from [<8079a4c8>] (__refcount_add.constprop.0+0x4c/0x50) | [<8079a47c>] (__refcount_add.constprop.0) from [<8079a57c>] (can_put_echo_skb+0xb0/0x13c) | [<8079a4cc>] (can_put_echo_skb) from [<8079ba98>] (flexcan_start_xmit+0x1c4/0x230) r9:00000010 r8:83f48610 r7:0fdc0000 r6:0c080000 r5:82b44000 r4:834e5600 | [<8079b8d4>] (flexcan_start_xmit) from [<80969078>] (netdev_start_xmit+0x44/0x70) r9:814c0ba0 r8:80c8790c r7:00000000 r6:834e5600 r5:82b44000 r4:82ab1f00 | [<80969034>] (netdev_start_xmit) from [<809725a4>] (dev_hard_start_xmit+0x19c/0x318) r9:814c0ba0 r8:00000000 r7:82ab1f00 r6:82b44000 r5:00000000 r4:834e5600 | [<80972408>] (dev_hard_start_xmit) from [<809c6584>] (sch_direct_xmit+0xcc/0x264) r10:834e5600 r9:00000000 r8:00000000 r7:82b44000 r6:82ab1f00 r5:834e5600 r4:83f27400 | [<809c64b8>] (sch_direct_xmit) from [<809c6c0c>] (__qdisc_run+0x4f0/0x534) To fix this problem, only set skb ownership to sockets which have still a ref count > 0. Fixes: 0ae89beb283a ("can: add destructor for self generated skbs") Cc: Oliver Hartkopp <socketcan@hartkopp.net> Cc: Andre Naujoks <nautsch2@gmail.com> Link: https://lore.kernel.org/r/20210226092456.27126-1-o.rempel@pengutronix.de Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Reviewed-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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Oleksij Rempel
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fc8d027b39 |
can: can_create_echo_skb(): fix echo skb generation: always use skb_clone()
[ Upstream commit 286228d382ba6320f04fa2e7c6fc8d4d92e428f4 ] All user space generated SKBs are owned by a socket (unless injected into the key via AF_PACKET). If a socket is closed, all associated skbs will be cleaned up. This leads to a problem when a CAN driver calls can_put_echo_skb() on a unshared SKB. If the socket is closed prior to the TX complete handler, can_get_echo_skb() and the subsequent delivering of the echo SKB to all registered callbacks, a SKB with a refcount of 0 is delivered. To avoid the problem, in can_get_echo_skb() the original SKB is now always cloned, regardless of shared SKB or not. If the process exists it can now safely discard its SKBs, without disturbing the delivery of the echo SKB. The problem shows up in the j1939 stack, when it clones the incoming skb, which detects the already 0 refcount. We can easily reproduce this with following example: testj1939 -B -r can0: & cansend can0 1823ff40#0123 WARNING: CPU: 0 PID: 293 at lib/refcount.c:25 refcount_warn_saturate+0x108/0x174 refcount_t: addition on 0; use-after-free. Modules linked in: coda_vpu imx_vdoa videobuf2_vmalloc dw_hdmi_ahb_audio vcan CPU: 0 PID: 293 Comm: cansend Not tainted 5.5.0-rc6-00376-g9e20dcb7040d #1 Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) Backtrace: [<c010f570>] (dump_backtrace) from [<c010f90c>] (show_stack+0x20/0x24) [<c010f8ec>] (show_stack) from [<c0c3e1a4>] (dump_stack+0x8c/0xa0) [<c0c3e118>] (dump_stack) from [<c0127fec>] (__warn+0xe0/0x108) [<c0127f0c>] (__warn) from [<c01283c8>] (warn_slowpath_fmt+0xa8/0xcc) [<c0128324>] (warn_slowpath_fmt) from [<c0539c0c>] (refcount_warn_saturate+0x108/0x174) [<c0539b04>] (refcount_warn_saturate) from [<c0ad2cac>] (j1939_can_recv+0x20c/0x210) [<c0ad2aa0>] (j1939_can_recv) from [<c0ac9dc8>] (can_rcv_filter+0xb4/0x268) [<c0ac9d14>] (can_rcv_filter) from [<c0aca2cc>] (can_receive+0xb0/0xe4) [<c0aca21c>] (can_receive) from [<c0aca348>] (can_rcv+0x48/0x98) [<c0aca300>] (can_rcv) from [<c09b1fdc>] (__netif_receive_skb_one_core+0x64/0x88) [<c09b1f78>] (__netif_receive_skb_one_core) from [<c09b2070>] (__netif_receive_skb+0x38/0x94) [<c09b2038>] (__netif_receive_skb) from [<c09b2130>] (netif_receive_skb_internal+0x64/0xf8) [<c09b20cc>] (netif_receive_skb_internal) from [<c09b21f8>] (netif_receive_skb+0x34/0x19c) [<c09b21c4>] (netif_receive_skb) from [<c0791278>] (can_rx_offload_napi_poll+0x58/0xb4) Fixes: 0ae89beb283a ("can: add destructor for self generated skbs") Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Link: http://lore.kernel.org/r/20200124132656.22156-1-o.rempel@pengutronix.de Acked-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Sasha Levin <sashal@kernel.org> |
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Kaixu Xia
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590eaf1fec |
Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com> |