2 Commits

Author	SHA1	Message	Date
Jiri Olsa	8e9af82171	selftests/bpf: Move kfunc exports to bpf_testmod/bpf_testmod_kfunc.h ... Move all kfunc exports into separate bpf_testmod_kfunc.h header file and include it in tests that need it. We will move all test kfuncs into bpf_testmod in following change, so it's convenient to have declarations in single place. The bpf_testmod_kfunc.h is included by both bpf_testmod and bpf programs that use test kfuncs. As suggested by David, the bpf_testmod_kfunc.h includes vmlinux.h and bpf/bpf_helpers.h for bpf programs build, so the declarations have proper __ksym attribute and we can resolve all the structs. Note in kfunc_call_test_subprog.c we can no longer use the sk_state define from bpf_tcp_helpers.h (because it clashed with vmlinux.h) and we need to address __sk_common.skc_state field directly. Acked-by: David Vernet <void@manifault.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20230515133756.1658301-3-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>	2023-05-16 22:09:23 -07:00
Kumar Kartikeya Dwivedi	4656569643	selftests/bpf: Add test for race in btf_try_get_module ... This adds a complete test case to ensure we never take references to modules not in MODULE_STATE_LIVE, which can lead to UAF, and it also ensures we never access btf->kfunc_set_tab in an inconsistent state. The test uses userfaultfd to artificially widen the race. When run on an unpatched kernel, it leads to the following splat: [root@(none) bpf]# ./test_progs -t bpf_mod_race/ksym [ 55.498171] BUG: unable to handle page fault for address: fffffbfff802548b [ 55.499206] #PF: supervisor read access in kernel mode [ 55.499855] #PF: error_code(0x0000) - not-present page [ 55.500555] PGD a4fa9067 P4D a4fa9067 PUD a4fa5067 PMD 1b44067 PTE 0 [ 55.501499] Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI [ 55.502195] CPU: 0 PID: 83 Comm: kworker/0:2 Tainted: G OE 5.16.0-rc4+ #151 [ 55.503388] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ArchLinux 1.15.0-1 04/01/2014 [ 55.504777] Workqueue: events bpf_prog_free_deferred [ 55.505563] RIP: 0010:kasan_check_range+0x184/0x1d0 [ 55.509140] RSP: 0018:ffff88800560fcf0 EFLAGS: 00010282 [ 55.509977] RAX: fffffbfff802548b RBX: fffffbfff802548c RCX: ffffffff9337b6ba [ 55.511096] RDX: fffffbfff802548c RSI: 0000000000000004 RDI: ffffffffc012a458 [ 55.512143] RBP: fffffbfff802548b R08: 0000000000000001 R09: ffffffffc012a45b [ 55.513228] R10: fffffbfff802548b R11: 0000000000000001 R12: ffff888001b5f598 [ 55.514332] R13: ffff888004f49ac8 R14: 0000000000000000 R15: ffff888092449400 [ 55.515418] FS: 0000000000000000(0000) GS:ffff888092400000(0000) knlGS:0000000000000000 [ 55.516705] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 55.517560] CR2: fffffbfff802548b CR3: 0000000007c10006 CR4: 0000000000770ef0 [ 55.518672] PKRU: 55555554 [ 55.519022] Call Trace: [ 55.519483] <TASK> [ 55.519884] module_put.part.0+0x2a/0x180 [ 55.520642] bpf_prog_free_deferred+0x129/0x2e0 [ 55.521478] process_one_work+0x4fa/0x9e0 [ 55.522122] ? pwq_dec_nr_in_flight+0x100/0x100 [ 55.522878] ? rwlock_bug.part.0+0x60/0x60 [ 55.523551] worker_thread+0x2eb/0x700 [ 55.524176] ? __kthread_parkme+0xd8/0xf0 [ 55.524853] ? process_one_work+0x9e0/0x9e0 [ 55.525544] kthread+0x23a/0x270 [ 55.526088] ? set_kthread_struct+0x80/0x80 [ 55.526798] ret_from_fork+0x1f/0x30 [ 55.527413] </TASK> [ 55.527813] Modules linked in: bpf_testmod(OE) [last unloaded: bpf_testmod] [ 55.530846] CR2: fffffbfff802548b [ 55.531341] ---[ end trace 1af41803c054ad6d ]--- [ 55.532136] RIP: 0010:kasan_check_range+0x184/0x1d0 [ 55.535887] RSP: 0018:ffff88800560fcf0 EFLAGS: 00010282 [ 55.536711] RAX: fffffbfff802548b RBX: fffffbfff802548c RCX: ffffffff9337b6ba [ 55.537821] RDX: fffffbfff802548c RSI: 0000000000000004 RDI: ffffffffc012a458 [ 55.538899] RBP: fffffbfff802548b R08: 0000000000000001 R09: ffffffffc012a45b [ 55.539928] R10: fffffbfff802548b R11: 0000000000000001 R12: ffff888001b5f598 [ 55.541021] R13: ffff888004f49ac8 R14: 0000000000000000 R15: ffff888092449400 [ 55.542108] FS: 0000000000000000(0000) GS:ffff888092400000(0000) knlGS:0000000000000000 [ 55.543260]CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 55.544136] CR2: fffffbfff802548b CR3: 0000000007c10006 CR4: 0000000000770ef0 [ 55.545317] PKRU: 55555554 [ 55.545671] note: kworker/0:2[83] exited with preempt_count 1 Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20220114163953.1455836-11-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>	2022-01-18 14:27:39 -08:00