Lorenz Bauer 076bc6ebce bpf: Fix OOB read when printing XDP link fdinfo ... [ Upstream commit d6371c76e20d7d3f61b05fd67b596af4d14a8886 ] We got the following UBSAN report on one of our testing machines: ================================================================================ UBSAN: array-index-out-of-bounds in kernel/bpf/syscall.c:2389:24 index 6 is out of range for type 'char *[6]' CPU: 43 PID: 930921 Comm: systemd-coredum Tainted: G O 5.10.48-cloudflare-kasan-2021.7.0 #1 Hardware name: <snip> Call Trace: dump_stack+0x7d/0xa3 ubsan_epilogue+0x5/0x40 __ubsan_handle_out_of_bounds.cold+0x43/0x48 ? seq_printf+0x17d/0x250 bpf_link_show_fdinfo+0x329/0x380 ? bpf_map_value_size+0xe0/0xe0 ? put_files_struct+0x20/0x2d0 ? __kasan_kmalloc.constprop.0+0xc2/0xd0 seq_show+0x3f7/0x540 seq_read_iter+0x3f8/0x1040 seq_read+0x329/0x500 ? seq_read_iter+0x1040/0x1040 ? __fsnotify_parent+0x80/0x820 ? __fsnotify_update_child_dentry_flags+0x380/0x380 vfs_read+0x123/0x460 ksys_read+0xed/0x1c0 ? __x64_sys_pwrite64+0x1f0/0x1f0 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 <snip> ================================================================================ ================================================================================ UBSAN: object-size-mismatch in kernel/bpf/syscall.c:2384:2 From the report, we can infer that some array access in bpf_link_show_fdinfo at index 6 is out of bounds. The obvious candidate is bpf_link_type_strs[BPF_LINK_TYPE_XDP] with BPF_LINK_TYPE_XDP == 6. It turns out that BPF_LINK_TYPE_XDP is missing from bpf_types.h and therefore doesn't have an entry in bpf_link_type_strs: pos: 0 flags: 02000000 mnt_id: 13 link_type: (null) link_id: 4 prog_tag: bcf7977d3b93787c prog_id: 4 ifindex: 1 Fixes: aa8d3a716b ("bpf, xdp: Add bpf_link-based XDP attachment API") Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210719085134.43325-2-lmb@cloudflare.com Signed-off-by: Sasha Levin <sashal@kernel.org>		2021-08-04 12:46:41 +02:00
..
acpi	ACPI: scan: Use unique number for instance_no	2021-03-30 14:32:06 +02:00
asm-generic	sched/core: Initialize the idle task with preemption disabled	2021-07-14 16:55:50 +02:00
clocksource	clocksource/drivers/timer-ti-dm: Save and restore timer TIOCP_CFG	2021-07-14 16:56:12 +02:00
crypto	crypto: shash - avoid comparing pointers to exported functions under CFI	2021-07-14 16:55:54 +02:00
drm	drm: Return -ENOTTY for non-drm ioctls	2021-07-28 14:35:47 +02:00
dt-bindings	clk: imx8mq: remove SYS PLL 1/2 clock gates	2021-07-14 16:56:20 +02:00
keys	certs: Add EFI_CERT_X509_GUID support for dbx entries	2021-06-30 08:47:30 -04:00
kunit	kunit: fix display of failed expectations for strings	2020-11-10 13:45:15 -07:00
kvm	ARM:	2020-10-23 11:17:56 -07:00
linux	bpf: Fix OOB read when printing XDP link fdinfo	2021-08-04 12:46:41 +02:00
math-emu
media	media: subdev: disallow ioctl for saa6588/davinci	2021-07-19 09:45:02 +02:00
memory
misc
net	sctp: move 198 addresses from unusable to private scope	2021-07-31 08:16:11 +02:00
pcmcia
ras
rdma	RDMA: Lift ibdev_to_node from rds to common code	2021-02-26 10:12:59 +01:00
scsi	scsi: iscsi: Fix conn use after free during resets	2021-07-20 16:05:41 +02:00
soc	net: dsa: felix: implement port flushing on .phylink_mac_link_down	2021-02-17 11:02:27 +01:00
sound	ALSA: hda: intel-nhlt: verify config type	2021-03-09 11:11:14 +01:00
target	scsi: target: core: Add cmd length set before cmd complete	2021-03-17 17:06:25 +01:00
trace	afs: Fix tracepoint string placement with built-in AFS	2021-07-28 14:35:41 +02:00
uapi	net: fix mistake path for netdev_features_strings	2021-07-19 09:44:51 +02:00
vdso
video	gpu: ipu-v3: remove unused functions	2020-10-26 10:42:38 +01:00
xen	Xen/gntdev: correct error checking in gntdev_map_grant_pages()	2021-02-23 15:53:24 +01:00