mainlining shenanigans
Syzkaller was able to construct a packet of negative length by redirecting from bpf_prog_test_run_skb with BPF_PROG_TYPE_LWT_XMIT: BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:345 [inline] BUG: KASAN: slab-out-of-bounds in skb_copy_from_linear_data include/linux/skbuff.h:3421 [inline] BUG: KASAN: slab-out-of-bounds in __pskb_copy_fclone+0x2dd/0xeb0 net/core/skbuff.c:1395 Read of size 4294967282 at addr ffff8801d798009c by task syz-executor2/12942 kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267 memcpy+0x23/0x50 mm/kasan/kasan.c:302 memcpy include/linux/string.h:345 [inline] skb_copy_from_linear_data include/linux/skbuff.h:3421 [inline] __pskb_copy_fclone+0x2dd/0xeb0 net/core/skbuff.c:1395 __pskb_copy include/linux/skbuff.h:1053 [inline] pskb_copy include/linux/skbuff.h:2904 [inline] skb_realloc_headroom+0xe7/0x120 net/core/skbuff.c:1539 ipip6_tunnel_xmit net/ipv6/sit.c:965 [inline] sit_tunnel_xmit+0xe1b/0x30d0 net/ipv6/sit.c:1029 __netdev_start_xmit include/linux/netdevice.h:4325 [inline] netdev_start_xmit include/linux/netdevice.h:4334 [inline] xmit_one net/core/dev.c:3219 [inline] dev_hard_start_xmit+0x295/0xc90 net/core/dev.c:3235 __dev_queue_xmit+0x2f0d/0x3950 net/core/dev.c:3805 dev_queue_xmit+0x17/0x20 net/core/dev.c:3838 __bpf_tx_skb net/core/filter.c:2016 [inline] __bpf_redirect_common net/core/filter.c:2054 [inline] __bpf_redirect+0x5cf/0xb20 net/core/filter.c:2061 ____bpf_clone_redirect net/core/filter.c:2094 [inline] bpf_clone_redirect+0x2f6/0x490 net/core/filter.c:2066 bpf_prog_41f2bcae09cd4ac3+0xb25/0x1000 The generated test constructs a packet with mac header, network header, skb->data pointing to network header and skb->len 0. Redirecting to a sit0 through __bpf_redirect_no_mac pulls the mac length, even though skb->data already is at skb->network_header. bpf_prog_test_run_skb has already pulled it as LWT_XMIT !is_l2. Update the offset calculation to pull only if skb->data differs from skb->network_header, which is not true in this case. The test itself can be run only from commit |
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arch | ||
block | ||
certs | ||
crypto | ||
Documentation | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
LICENSES | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | ||
.cocciconfig | ||
.get_maintainer.ignore | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
COPYING | ||
CREDITS | ||
Kbuild | ||
Kconfig | ||
MAINTAINERS | ||
Makefile | ||
README |
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.