user/sven/linux.git/tools/testing, branch v5.4.38

bpf: Forbid XADD on spilled pointers for unprivileged users

2020-05-02T06:48:46Z

commit 6e7e63cbb023976d828cdb22422606bf77baa8a9 upstream. When check_xadd() verifies an XADD operation on a pointer to a stack slot containing a spilled pointer, check_stack_read() verifies that the read, which is part of XADD, is valid. However, since the placeholder value -1 is passed as `value_regno`, check_stack_read() can only return a binary decision and can't return the type of the value that was read. The intent here is to verify whether the value read from the stack slot may be used as a SCALAR_VALUE; but since check_stack_read() doesn't check the type, and the type information is lost when check_stack_read() returns, this is not enforced, and a malicious user can abuse XADD to leak spilled kernel pointers. Fix it by letting check_stack_read() verify that the value is usable as a SCALAR_VALUE if no type information is passed to the caller. To be able to use __is_pointer_value() in check_stack_read(), move it up. Fix up the expected unprivileged error message for a BPF selftest that, until now, assumed that unprivileged users can use XADD on stack-spilled pointers. This also gives us a test for the behavior introduced in this patch for free. In theory, this could also be fixed by forbidding XADD on stack spills entirely, since XADD is a locked operation (for operations on memory with concurrency) and there can't be any concurrency on the BPF stack; but Alexei has said that he wants to keep XADD on stack slots working to avoid changes to the test suite [1]. The following BPF program demonstrates how to leak a BPF map pointer as an unprivileged user using this bug: // r7 = map_pointer BPF_LD_MAP_FD(BPF_REG_7, small_map), // r8 = launder(map_pointer) BPF_STX_MEM(BPF_DW, BPF_REG_FP, BPF_REG_7, -8), BPF_MOV64_IMM(BPF_REG_1, 0), ((struct bpf_insn) { .code = BPF_STX | BPF_DW | BPF_XADD, .dst_reg = BPF_REG_FP, .src_reg = BPF_REG_1, .off = -8 }), BPF_LDX_MEM(BPF_DW, BPF_REG_8, BPF_REG_FP, -8), // store r8 into map BPF_MOV64_REG(BPF_REG_ARG1, BPF_REG_7), BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_FP), BPF_ALU64_IMM(BPF_ADD, BPF_REG_ARG2, -4), BPF_ST_MEM(BPF_W, BPF_REG_ARG2, 0, 0), BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), BPF_EXIT_INSN(), BPF_STX_MEM(BPF_DW, BPF_REG_0, BPF_REG_8, 0), BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN() [1] https://lore.kernel.org/bpf/20200416211116.qxqcza5vo2ddnkdq@ast-mbp.dhcp.thefacebook.com/ Fixes: 17a5267067f3 ("bpf: verifier (add verifier core)") Signed-off-by: Jann Horn Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200417000007.10734-1-jannh@google.com Signed-off-by: Greg Kroah-Hartman

selftests: Fix suppress test in fib_tests.sh

2020-04-29T14:33:09Z

[ Upstream commit 2c1dd4c110627c2a4f006643f074119205cfcff4 ] fib_tests is spewing errors: ... Cannot open network namespace "ns1": No such file or directory Cannot open network namespace "ns1": No such file or directory Cannot open network namespace "ns1": No such file or directory Cannot open network namespace "ns1": No such file or directory ping: connect: Network is unreachable Cannot open network namespace "ns1": No such file or directory Cannot open network namespace "ns1": No such file or directory ... Each test entry in fib_tests is supposed to do its own setup and cleanup. Right now the $IP commands in fib_suppress_test are failing because there is no ns1. Add the setup/cleanup and logging expected for each test. Fixes: ca7a03c41753 ("ipv6: do not free rt if FIB_LOOKUP_NOREF is set on suppress rule") Signed-off-by: David Ahern Cc: Jason A. Donenfeld Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: Update fib_select_default to handle nexthop objects

2020-04-29T14:33:07Z

[ Upstream commit 7c74b0bec918c1e0ca0b4208038c156eacf8f13f ] A user reported [0] hitting the WARN_ON in fib_info_nh: [ 8633.839816] ------------[ cut here ]------------ [ 8633.839819] WARNING: CPU: 0 PID: 1719 at include/net/nexthop.h:251 fib_select_path+0x303/0x381 ... [ 8633.839846] RIP: 0010:fib_select_path+0x303/0x381 ... [ 8633.839848] RSP: 0018:ffffb04d407f7d00 EFLAGS: 00010286 [ 8633.839850] RAX: 0000000000000000 RBX: ffff9460b9897ee8 RCX: 00000000000000fe [ 8633.839851] RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000000000000000 [ 8633.839852] RBP: ffff946076049850 R08: 0000000059263a83 R09: ffff9460840e4000 [ 8633.839853] R10: 0000000000000014 R11: 0000000000000000 R12: ffffb04d407f7dc0 [ 8633.839854] R13: ffffffffa4ce3240 R14: 0000000000000000 R15: ffff9460b7681f60 [ 8633.839857] FS: 00007fcac2e02700(0000) GS:ffff9460bdc00000(0000) knlGS:0000000000000000 [ 8633.839858] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 8633.839859] CR2: 00007f27beb77e28 CR3: 0000000077734000 CR4: 00000000000006f0 [ 8633.839867] Call Trace: [ 8633.839871] ip_route_output_key_hash_rcu+0x421/0x890 [ 8633.839873] ip_route_output_key_hash+0x5e/0x80 [ 8633.839876] ip_route_output_flow+0x1a/0x50 [ 8633.839878] __ip4_datagram_connect+0x154/0x310 [ 8633.839880] ip4_datagram_connect+0x28/0x40 [ 8633.839882] __sys_connect+0xd6/0x100 ... The WARN_ON is triggered in fib_select_default which is invoked when there are multiple default routes. Update the function to use fib_info_nhc and convert the nexthop checks to use fib_nh_common. Add test case that covers the affected code path. [0] https://github.com/FRRouting/frr/issues/6089 Fixes: 493ced1ac47c ("ipv4: Allow routes to use nexthop objects") Signed-off-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tracing/selftests: Turn off timeout setting

2020-04-29T14:33:05Z

[ Upstream commit b43e78f65b1d35fd3e13c7b23f9b64ea83c9ad3a ] As the ftrace selftests can run for a long period of time, disable the timeout that the general selftests have. If a selftest hangs, then it probably means the machine will hang too. Link: https://lore.kernel.org/r/alpine.LSU.2.21.1911131604170.18679@pobox.suse.cz Suggested-by: Miroslav Benes Tested-by: Miroslav Benes Reviewed-by: Miroslav Benes Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sasha Levin

selftests: kmod: fix handling test numbers above 9

2020-04-29T14:33:00Z

[ Upstream commit 6d573a07528308eb77ec072c010819c359bebf6e ] get_test_count() and get_test_enabled() were broken for test numbers above 9 due to awk interpreting a field specification like '$0010' as octal rather than decimal. Fix it by stripping the leading zeroes. Signed-off-by: Eric Biggers Signed-off-by: Andrew Morton Acked-by: Luis Chamberlain Cc: Alexei Starovoitov Cc: Greg Kroah-Hartman Cc: Jeff Vander Stoep Cc: Jessica Yu Cc: Kees Cook Cc: NeilBrown Link: http://lkml.kernel.org/r/20200318230515.171692-5-ebiggers@kernel.org Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

tools/test/nvdimm: Fix out of tree build

2020-04-29T14:32:59Z

[ Upstream commit 1f776799628139d0da47e710ad86eb58d987ff66 ] Out of tree build using make M=tools/test/nvdimm O=/tmp/build -C /tmp/build fails with the following error make: Entering directory '/tmp/build' CC [M] tools/testing/nvdimm/test/nfit.o linux/tools/testing/nvdimm/test/nfit.c:19:10: fatal error: nd-core.h: No such file or directory 19 | #include | ^~~~~~~~~~~ compilation terminated. That is because the kbuild file uses $(src) which points to tools/testing/nvdimm, $(srctree) correctly points to root of the linux source tree. Reported-by: Aneesh Kumar K.V Signed-off-by: Santosh Sivaraj Link: https://lore.kernel.org/r/20200114054051.4115790-1-santosh@fossix.org Signed-off-by: Dan Williams Signed-off-by: Sasha Levin

tools/testing/nvdimm: Fix compilation failure without CONFIG_DEV_DAX_PMEM_COMPAT

2020-04-29T14:32:57Z

[ Upstream commit c0e71d602053e4e7637e4bc7d0bc9603ea77a33f ] When a kernel is configured without CONFIG_DEV_DAX_PMEM_COMPAT, the compilation of tools/testing/nvdimm fails with: Building modules, stage 2. MODPOST 11 modules ERROR: "dax_pmem_compat_test" [tools/testing/nvdimm/test/nfit_test.ko] undefined! Fix the problem by calling dax_pmem_compat_test() only if the kernel has the required functionality. Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20200123154720.12097-1-jack@suse.cz Signed-off-by: Dan Williams Signed-off-by: Sasha Levin

bpf, test_verifier: switch bpf_get_stack's 0 s> r8 test

2020-04-23T08:36:46Z

[ no upstream commit ] Switch the comparison, so that is_branch_taken() will recognize that below branch is never taken: [...] 17: [...] R1_w=inv0 [...] R8_w=inv(id=0,smin_value=-2147483648,smax_value=-1,umin_value=18446744071562067968,var_off=(0xffffffff80000000; 0x7fffffff)) [...] 17: (67) r8 <<= 32 18: [...] R8_w=inv(id=0,smax_value=-4294967296,umin_value=9223372036854775808,umax_value=18446744069414584320,var_off=(0x8000000000000000; 0x7fffffff00000000)) [...] 18: (c7) r8 s>>= 32 19: [...] R8_w=inv(id=0,smin_value=-2147483648,smax_value=-1,umin_value=18446744071562067968,var_off=(0xffffffff80000000; 0x7fffffff)) [...] 19: (6d) if r1 s> r8 goto pc+16 [...] R1_w=inv0 [...] R8_w=inv(id=0,smin_value=-2147483648,smax_value=-1,umin_value=18446744071562067968,var_off=(0xffffffff80000000; 0x7fffffff)) [...] [...] Currently we check for is_branch_taken() only if either K is source, or source is a scalar value that is const. For upstream it would be good to extend this properly to check whether dst is const and src not. For the sake of the test_verifier, it is probably not needed here: # ./test_verifier 101 #101/p bpf_get_stack return R0 within range OK Summary: 1 PASSED, 0 SKIPPED, 0 FAILED I haven't seen this issue in test_progs* though, they are passing fine: # ./test_progs-no_alu32 -t get_stack Switching to flavor 'no_alu32' subdirectory... #20 get_stack_raw_tp:OK Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED # ./test_progs -t get_stack #20 get_stack_raw_tp:OK Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Acked-by: John Fastabend Signed-off-by: Greg Kroah-Hartman

bpf: Test_progs, add test to catch retval refine error handling

2020-04-23T08:36:46Z

commit d2db08c7a14e0b5eed6132baf258b80622e041a9 upstream. Before this series the verifier would clamp return bounds of bpf_get_stack() to [0, X] and this led the verifier to believe that a JMP_JSLT 0 would be false and so would prune that path. The result is anything hidden behind that JSLT would be unverified. Add a test to catch this case by hiding an goto pc-1 behind the check which will cause an infinite loop if not rejected. Signed-off-by: John Fastabend Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/158560423908.10843.11783152347709008373.stgit@john-Precision-5820-Tower Signed-off-by: Daniel Borkmann Signed-off-by: Greg Kroah-Hartman

bpf: Test_verifier, bpf_get_stack return value add <0

2020-04-23T08:36:46Z

commit 9ac26e9973bac5716a2a542e32f380c84db2b88c upstream. With current ALU32 subreg handling and retval refine fix from last patches we see an expected failure in test_verifier. With verbose verifier state being printed at each step for clarity we have the following relavent lines [I omit register states that are not necessarily useful to see failure cause], #101/p bpf_get_stack return R0 within range FAIL Failed to load prog 'Success'! [..] 14: (85) call bpf_get_stack#67 R0_w=map_value(id=0,off=0,ks=8,vs=48,imm=0) R3_w=inv48 15: R0=inv(id=0,smax_value=48,var32_off=(0x0; 0xffffffff)) 15: (b7) r1 = 0 16: R0=inv(id=0,smax_value=48,var32_off=(0x0; 0xffffffff)) R1_w=inv0 16: (bf) r8 = r0 17: R0=inv(id=0,smax_value=48,var32_off=(0x0; 0xffffffff)) R1_w=inv0 R8_w=inv(id=0,smax_value=48,var32_off=(0x0; 0xffffffff)) 17: (67) r8 <<= 32 18: R0=inv(id=0,smax_value=48,var32_off=(0x0; 0xffffffff)) R1_w=inv0 R8_w=inv(id=0,smax_value=9223372032559808512, umax_value=18446744069414584320, var_off=(0x0; 0xffffffff00000000), s32_min_value=0, s32_max_value=0, u32_max_value=0, var32_off=(0x0; 0x0)) 18: (c7) r8 s>>= 32 19 R0=inv(id=0,smax_value=48,var32_off=(0x0; 0xffffffff)) R1_w=inv0 R8_w=inv(id=0,smin_value=-2147483648, smax_value=2147483647, var32_off=(0x0; 0xffffffff)) 19: (cd) if r1 s< r8 goto pc+16 R0=inv(id=0,smax_value=48,var32_off=(0x0; 0xffffffff)) R1_w=inv0 R8_w=inv(id=0,smin_value=-2147483648, smax_value=0, var32_off=(0x0; 0xffffffff)) 20: R0=inv(id=0,smax_value=48,var32_off=(0x0; 0xffffffff)) R1_w=inv0 R8_w=inv(id=0,smin_value=-2147483648, smax_value=0, R9=inv48 20: (1f) r9 -= r8 21: (bf) r2 = r7 22: R2_w=map_value(id=0,off=0,ks=8,vs=48,imm=0) 22: (0f) r2 += r8 value -2147483648 makes map_value pointer be out of bounds After call bpf_get_stack() on line 14 and some moves we have at line 16 an r8 bound with max_value 48 but an unknown min value. This is to be expected bpf_get_stack call can only return a max of the input size but is free to return any negative error in the 32-bit register space. The C helper is returning an int so will use lower 32-bits. Lines 17 and 18 clear the top 32 bits with a left/right shift but use ARSH so we still have worst case min bound before line 19 of -2147483648. At this point the signed check 'r1 s< r8' meant to protect the addition on line 22 where dst reg is a map_value pointer may very well return true with a large negative number. Then the final line 22 will detect this as an invalid operation and fail the program. What we want to do is proceed only if r8 is positive non-error. So change 'r1 s< r8' to 'r1 s> r8' so that we jump if r8 is negative. Next we will throw an error because we access past the end of the map value. The map value size is 48 and sizeof(struct test_val) is 48 so we walk off the end of the map value on the second call to get bpf_get_stack(). Fix this by changing sizeof(struct test_val) to 24 by using 'sizeof(struct test_val) / 2'. After this everything passes as expected. Signed-off-by: John Fastabend Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/158560426019.10843.3285429543232025187.stgit@john-Precision-5820-Tower Signed-off-by: Greg Kroah-Hartman