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authorEric Dumazet <edumazet@google.com>2023-02-08 15:25:08 +0100
committerJakub Kicinski <kuba@kernel.org>2023-02-09 18:57:23 +0100
commit0b34d68049b09821499b93d50b5a9d7d2ca449f6 (patch)
treeccf461aadf9fabff325a684e66dca724109fd7b8 /include/uapi
parentMerge tag 'linux-can-next-for-6.3-20230208' of git://git.kernel.org/pub/scm/l... (diff)
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net: enable usercopy for skb_small_head_cache
syzbot and other bots reported that we have to enable user copy to/from skb->head. [1] We can prevent access to skb_shared_info, which is a nice improvement over standard kmem_cache. Layout of these kmem_cache objects is: < SKB_SMALL_HEAD_HEADROOM >< struct skb_shared_info > usercopy: Kernel memory overwrite attempt detected to SLUB object 'skbuff_small_head' (offset 32, size 20)! ------------[ cut here ]------------ kernel BUG at mm/usercopy.c:102 ! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.2.0-rc6-syzkaller-01425-gcb6b2e11a42d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 RIP: 0010:usercopy_abort+0xbd/0xbf mm/usercopy.c:102 Code: e8 ee ad ba f7 49 89 d9 4d 89 e8 4c 89 e1 41 56 48 89 ee 48 c7 c7 20 2b 5b 8a ff 74 24 08 41 57 48 8b 54 24 20 e8 7a 17 fe ff <0f> 0b e8 c2 ad ba f7 e8 7d fb 08 f8 48 8b 0c 24 49 89 d8 44 89 ea RSP: 0000:ffffc90000067a48 EFLAGS: 00010286 RAX: 000000000000006b RBX: ffffffff8b5b6ea0 RCX: 0000000000000000 RDX: ffff8881401c0000 RSI: ffffffff8166195c RDI: fffff5200000cf3b RBP: ffffffff8a5b2a60 R08: 000000000000006b R09: 0000000000000000 R10: 0000000080000000 R11: 0000000000000000 R12: ffffffff8bf2a925 R13: ffffffff8a5b29a0 R14: 0000000000000014 R15: ffffffff8a5b2960 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000000c48e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __check_heap_object+0xdd/0x110 mm/slub.c:4761 check_heap_object mm/usercopy.c:196 [inline] __check_object_size mm/usercopy.c:251 [inline] __check_object_size+0x1da/0x5a0 mm/usercopy.c:213 check_object_size include/linux/thread_info.h:199 [inline] check_copy_size include/linux/thread_info.h:235 [inline] copy_from_iter include/linux/uio.h:186 [inline] copy_from_iter_full include/linux/uio.h:194 [inline] memcpy_from_msg include/linux/skbuff.h:3977 [inline] qrtr_sendmsg+0x65f/0x970 net/qrtr/af_qrtr.c:965 sock_sendmsg_nosec net/socket.c:722 [inline] sock_sendmsg+0xde/0x190 net/socket.c:745 say_hello+0xf6/0x170 net/qrtr/ns.c:325 qrtr_ns_init+0x220/0x2b0 net/qrtr/ns.c:804 qrtr_proto_init+0x59/0x95 net/qrtr/af_qrtr.c:1296 do_one_initcall+0x141/0x790 init/main.c:1306 do_initcall_level init/main.c:1379 [inline] do_initcalls init/main.c:1395 [inline] do_basic_setup init/main.c:1414 [inline] kernel_init_freeable+0x6f9/0x782 init/main.c:1634 kernel_init+0x1e/0x1d0 init/main.c:1522 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 </TASK> Fixes: bf9f1baa279f ("net: add dedicated kmem_cache for typical/small skb->head") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Tested-by: Ido Schimmel <idosch@nvidia.com> Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> Tested-by: Linux Kernel Functional Testing <lkft@linaro.org> Link: https://lore.kernel.org/linux-next/CA+G9fYs-i-c2KTSA7Ai4ES_ZESY1ZnM=Zuo8P1jN00oed6KHMA@mail.gmail.com Link: https://lore.kernel.org/r/20230208142508.3278406-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/uapi')
0 files changed, 0 insertions, 0 deletions