From: Xuan Zhuo xuanzhuo@linux.alibaba.com
[ Upstream commit 5e21bb4e812566aef86fbb77c96a4ec0782286e4 ]
These two types of XDP progs (BPF_XDP_DEVMAP, BPF_XDP_CPUMAP) will not be executed directly in the driver, therefore we should also not directly run them from here. To run in these two situations, there must be further preparations done, otherwise these may cause a kernel panic.
For more details, see also dev_xdp_attach().
[ 46.982479] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 46.984295] #PF: supervisor read access in kernel mode [ 46.985777] #PF: error_code(0x0000) - not-present page [ 46.987227] PGD 800000010dca4067 P4D 800000010dca4067 PUD 10dca6067 PMD 0 [ 46.989201] Oops: 0000 [#1] SMP PTI [ 46.990304] CPU: 7 PID: 562 Comm: a.out Not tainted 5.13.0+ #44 [ 46.992001] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/24 [ 46.995113] RIP: 0010:___bpf_prog_run+0x17b/0x1710 [ 46.996586] Code: 49 03 14 cc e8 76 f6 fe ff e9 ad fe ff ff 0f b6 43 01 48 0f bf 4b 02 48 83 c3 08 89 c2 83 e0 0f c0 ea 04 02 [ 47.001562] RSP: 0018:ffffc900005afc58 EFLAGS: 00010246 [ 47.003115] RAX: 0000000000000000 RBX: ffffc9000023f068 RCX: 0000000000000000 [ 47.005163] RDX: 0000000000000000 RSI: 0000000000000079 RDI: ffffc900005afc98 [ 47.007135] RBP: 0000000000000000 R08: ffffc9000023f048 R09: c0000000ffffdfff [ 47.009171] R10: 0000000000000001 R11: ffffc900005afb40 R12: ffffc900005afc98 [ 47.011172] R13: 0000000000000001 R14: 0000000000000001 R15: ffffffff825258a8 [ 47.013244] FS: 00007f04a5207580(0000) GS:ffff88842fdc0000(0000) knlGS:0000000000000000 [ 47.015705] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 47.017475] CR2: 0000000000000000 CR3: 0000000100182005 CR4: 0000000000770ee0 [ 47.019558] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 47.021595] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 47.023574] PKRU: 55555554 [ 47.024571] Call Trace: [ 47.025424] __bpf_prog_run32+0x32/0x50 [ 47.026296] ? printk+0x53/0x6a [ 47.027066] ? ktime_get+0x39/0x90 [ 47.027895] bpf_test_run.cold.28+0x23/0x123 [ 47.028866] ? printk+0x53/0x6a [ 47.029630] bpf_prog_test_run_xdp+0x149/0x1d0 [ 47.030649] __sys_bpf+0x1305/0x23d0 [ 47.031482] __x64_sys_bpf+0x17/0x20 [ 47.032316] do_syscall_64+0x3a/0x80 [ 47.033165] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 47.034254] RIP: 0033:0x7f04a51364dd [ 47.035133] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 48 [ 47.038768] RSP: 002b:00007fff8f9fc518 EFLAGS: 00000213 ORIG_RAX: 0000000000000141 [ 47.040344] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f04a51364dd [ 47.041749] RDX: 0000000000000048 RSI: 0000000020002a80 RDI: 000000000000000a [ 47.043171] RBP: 00007fff8f9fc530 R08: 0000000002049300 R09: 0000000020000100 [ 47.044626] R10: 0000000000000004 R11: 0000000000000213 R12: 0000000000401070 [ 47.046088] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 47.047579] Modules linked in: [ 47.048318] CR2: 0000000000000000 [ 47.049120] ---[ end trace 7ad34443d5be719a ]--- [ 47.050273] RIP: 0010:___bpf_prog_run+0x17b/0x1710 [ 47.051343] Code: 49 03 14 cc e8 76 f6 fe ff e9 ad fe ff ff 0f b6 43 01 48 0f bf 4b 02 48 83 c3 08 89 c2 83 e0 0f c0 ea 04 02 [ 47.054943] RSP: 0018:ffffc900005afc58 EFLAGS: 00010246 [ 47.056068] RAX: 0000000000000000 RBX: ffffc9000023f068 RCX: 0000000000000000 [ 47.057522] RDX: 0000000000000000 RSI: 0000000000000079 RDI: ffffc900005afc98 [ 47.058961] RBP: 0000000000000000 R08: ffffc9000023f048 R09: c0000000ffffdfff [ 47.060390] R10: 0000000000000001 R11: ffffc900005afb40 R12: ffffc900005afc98 [ 47.061803] R13: 0000000000000001 R14: 0000000000000001 R15: ffffffff825258a8 [ 47.063249] FS: 00007f04a5207580(0000) GS:ffff88842fdc0000(0000) knlGS:0000000000000000 [ 47.065070] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 47.066307] CR2: 0000000000000000 CR3: 0000000100182005 CR4: 0000000000770ee0 [ 47.067747] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 47.069217] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 47.070652] PKRU: 55555554 [ 47.071318] Kernel panic - not syncing: Fatal exception [ 47.072854] Kernel Offset: disabled [ 47.073683] ---[ end Kernel panic - not syncing: Fatal exception ]---
Fixes: 9216477449f3 ("bpf: cpumap: Add the possibility to attach an eBPF program to cpumap") Fixes: fbee97feed9b ("bpf: Add support to attach bpf program to a devmap entry") Reported-by: Abaci abaci@linux.alibaba.com Signed-off-by: Xuan Zhuo xuanzhuo@linux.alibaba.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Reviewed-by: Dust Li dust.li@linux.alibaba.com Acked-by: Jesper Dangaard Brouer brouer@redhat.com Acked-by: David Ahern dsahern@kernel.org Acked-by: Song Liu songliubraving@fb.com Link: https://lore.kernel.org/bpf/20210708080409.73525-1-xuanzhuo@linux.alibaba.co... Signed-off-by: Sasha Levin sashal@kernel.org --- net/bpf/test_run.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index 8b796c499cbb..e7cbd1b4a5e5 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -627,6 +627,9 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr, void *data; int ret;
+ if (prog->expected_attach_type == BPF_XDP_DEVMAP || + prog->expected_attach_type == BPF_XDP_CPUMAP) + return -EINVAL; if (kattr->test.ctx_in || kattr->test.ctx_out) return -EINVAL;