kernel/linux.git/tools/testing/selftests/bpf, branch v6.18.34

selftests/bpf: Remove test_access_variable_array

2026-05-23T11:07:21+00:00

commit aacee214d57636fa1f63007c65f333b5ea75a7a0 upstream. test_access_variable_array relied on accessing struct sched_domain::span to validate variable-length array handling via BTF. Recent scheduler refactoring removed or hid this field, causing the test to fail to build. Given that this test depends on internal scheduler structures that are subject to refactoring, and equivalent variable-length array coverage already exists via bpf_testmod-based tests, remove test_access_variable_array entirely. Link: https://lore.kernel.org/all/177434340048.1647592.8586759362906719839.tip-bot2@tip-bot2/ Signed-off-by: Venkat Rao Bagalkote Tested-by: Naveen Kumar Thummalapenta Link: https://lore.kernel.org/r/20260410105404.91126-1-venkat88@linux.ibm.com Signed-off-by: Alexei Starovoitov Signed-off-by: Greg Kroah-Hartman

bpf: allow UTF-8 literals in bpf_bprintf_prepare()

2026-05-23T11:06:52+00:00

[ Upstream commit b960430ea8862ef37ce53c8bf74a8dc79d3f2404 ] bpf_bprintf_prepare() only needs ASCII parsing for conversion specifiers. Plain text can safely carry bytes >= 0x80, so allow UTF-8 literals outside '%' sequences while keeping ASCII control bytes rejected and format specifiers ASCII-only. This keeps existing parsing rules for format directives unchanged, while allowing helpers such as bpf_trace_printk() to emit UTF-8 literal text. Update test_snprintf_negative() in the same commit so selftests keep matching the new plain-text vs format-specifier split during bisection. Fixes: 48cac3f4a96d ("bpf: Implement formatted output helpers with bstr_printf") Signed-off-by: Yihan Ding Acked-by: Paul Chaignon Link: https://lore.kernel.org/r/20260416120142.1420646-2-dingyihan@uniontech.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

selftests/bpf: Fix reg_bounds to match new tnum-based refinement

2026-05-23T11:06:32+00:00

[ Upstream commit 2fefa9c81a25534464911447d51ddb44b04a8e5b ] Commit efc11a667878 ("bpf: Improve bounds when tnum has a single possible value") improved the bounds refinement to detect when the tnum and u64 range overlap in a single value (and the bounds can thus be set to that value). Eduard then noticed that it broke the slow-mode reg_bounds selftests because they don't have an equivalent logic and are therefore unable to refine the bounds as much as the verifier. The following test case illustrates this. ACTUAL TRUE1: scalar(u64=0xffffffff00000000,u32=0,s64=0xffffffff00000000,s32=0) EXPECTED TRUE1: scalar(u64=[0xfffffffe00000001; 0xffffffff00000000],u32=0,s64=[0xfffffffe00000001; 0xffffffff00000000],s32=0) [...] #323/1007 reg_bounds_gen_consts_s64_s32/(s64)[0xfffffffe00000001; 0xffffffff00000000] (s32) S64_MIN:FAIL with the verifier logs: [...] 19: w0 = w6 ; R0=scalar(smin=0,smax=umax=0xffffffff, var_off=(0x0; 0xffffffff)) R6=scalar(smin=0xfffffffe00000001,smax=0xffffffff00000000, umin=0xfffffffe00000001,umax=0xffffffff00000000, var_off=(0xfffffffe00000000; 0x1ffffffff)) 20: w0 = w7 ; R0=0 R7=0x8000000000000000 21: if w6 == w7 goto pc+3 [...] from 21 to 25: [...] 25: w0 = w6 ; R0=0 R6=0xffffffff00000000 ; ^ ; unexpected refined value 26: w0 = w7 ; R0=0 R7=0x8000000000000000 27: exit When w6 == w7 is true, the verifier can deduce that the R6's tnum is equal to (0xfffffffe00000000; 0x100000000) and then use that information to refine the bounds: the tnum only overlap with the u64 range in 0xffffffff00000000. The reg_bounds selftest doesn't know about tnums and therefore fails to perform the same refinement. This issue happens when the tnum carries information that cannot be represented in the ranges, as otherwise the selftest could reach the same refined value using just the ranges. The tnum thus needs to represent non-contiguous values (ex., R6's tnum above, after the condition). The only way this can happen in the reg_bounds selftest is at the boundary between the 32 and 64bit ranges. We therefore only need to handle that case. This patch fixes the selftest refinement logic by checking if the u32 and u64 ranges overlap in a single value. If so, the ranges can be set to that value. We need to handle two cases: either they overlap in umin64... u64 values matching u32 range: xxx xxx xxx xxx |--------------------------------------| u64 range: 0 xxxxx UMAX64 or in umax64: u64 values matching u32 range: xxx xxx xxx xxx |--------------------------------------| u64 range: 0 xxxxx UMAX64 To detect the first case, we decrease umax64 to the maximum value that matches the u32 range. If that happens to be umin64, then umin64 is the only overlap. We proceed similarly for the second case, increasing umin64 to the minimum value that matches the u32 range. Note this is similar to how the verifier handles the general case using tnum, but we don't need to care about a single-value overlap in the middle of the range. That case is not possible when comparing two ranges. This patch also adds two test cases reproducing this bug as part of the normal test runs (without SLOW_TESTS=1). Fixes: efc11a667878 ("bpf: Improve bounds when tnum has a single possible value") Reported-by: Eduard Zingerman Closes: https://lore.kernel.org/bpf/4e6dd64a162b3cab3635706ae6abfdd0be4db5db.camel@gmail.com/ Signed-off-by: Paul Chaignon Link: https://lore.kernel.org/r/ada9UuSQi2SE2IfB@mail.gmail.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

selftests/bpf: fix __jited_unpriv tag name

2026-05-23T11:06:32+00:00

[ Upstream commit cdd54fe98c00549264a92613af6bb0e9a5fd0d1c ] __jited_unpriv was using "test_jited=" as its tag name, same as the priv variant __jited. Fix by using "test_jited_unpriv=". Fixes: 7d743e4c759c ("selftests/bpf: __jited test tag to check disassembly after jit") Acked-by: Ihor Solodrai Reviewed-by: Puranjay Mohan Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/r/20260410-selftests-global-tags-ordering-v2-1-c566ec9781bf@gmail.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

bpf: Relax scalar id equivalence for state pruning

2026-05-23T11:06:31+00:00

[ Upstream commit b0388bafa4949bd30af7b3be5ee415f2a25ac014 ] Scalar register IDs are used by the verifier to track relationships between registers and enable bounds propagation across those relationships. Once an ID becomes singular (i.e. only a single register/stack slot carries it), it can no longer contribute to bounds propagation and effectively becomes stale. The previous commit makes the verifier clear such ids before caching the state. When comparing the current and cached states for pruning, these stale IDs can cause technically equivalent states to be considered different and thus prevent pruning. For example, in the selftest added in the next commit, two registers - r6 and r7 are not linked to any other registers and get cached with id=0, in the current state, they are both linked to each other with id=A. Before this commit, check_scalar_ids would give temporary ids to r6 and r7 (say tid1 and tid2) and then check_ids() would map tid1->A, and when it would see tid2->A, it would not consider these state equivalent. Relax scalar ID equivalence by treating rold->id == 0 as "independent": if the old state did not rely on any ID relationships for a register, then any ID/linking present in the current state only adds constraints and is always safe to accept for pruning. Implement this by returning true immediately in check_scalar_ids() when old_id == 0. Maintain correctness for the opposite direction (old_id != 0 && cur_id == 0) by still allocating a temporary ID for cur_id == 0. This avoids incorrectly allowing multiple independent current registers (id==0) to satisfy a single linked old ID during mapping. Signed-off-by: Puranjay Mohan Link: https://lore.kernel.org/r/20260203165102.2302462-5-puranjay@kernel.org Signed-off-by: Alexei Starovoitov Stable-dep-of: 2f2ec8e7730e ("bpf: Enforce regsafe base id consistency for BPF_ADD_CONST scalars") Signed-off-by: Sasha Levin

bpf: Support negative offsets, BPF_SUB, and alu32 for linked register tracking

2026-05-23T11:06:30+00:00

[ Upstream commit 7a433e519364c3c19643e5c857f4fbfaebec441c ] Previously, the verifier only tracked positive constant deltas between linked registers using BPF_ADD. This limitation meant patterns like: r1 = r0; r1 += -4; if r1 s>= 0 goto l0_%=; // r1 >= 0 implies r0 >= 4 // verifier couldn't propagate bounds back to r0 if r0 != 0 goto l0_%=; r0 /= 0; // Verifier thinks this is reachable l0_%=: Similar limitation exists for 32-bit registers. With this change, the verifier can now track negative deltas in reg->off enabling bound propagation for the above pattern. For alu32, we make sure the destination register has the upper 32 bits as 0s before creating the link. BPF_ADD_CONST is split into BPF_ADD_CONST64 and BPF_ADD_CONST32, the latter is used in case of alu32 and sync_linked_regs uses this to zext the result if known_reg has this flag. Signed-off-by: Puranjay Mohan Acked-by: Eduard Zingerman Link: https://lore.kernel.org/r/20260204151741.2678118-2-puranjay@kernel.org Signed-off-by: Alexei Starovoitov Stable-dep-of: d7f14173c0d5 ("bpf: Fix linked reg delta tracking when src_reg == dst_reg") Signed-off-by: Sasha Levin

selftests/bpf: Test refinement of single-value tnum

2026-04-22T11:22:30+00:00

commit e6ad477d1bf8829973cddd9accbafa9d1a6cd15a upstream. This patch introduces selftests to cover the new bounds refinement logic introduced in the previous patch. Without the previous patch, the first two tests fail because of the invariant violation they trigger. The last test fails because the R10 access is not detected as dead code. In addition, all three tests fail because of R0 having a non-constant value in the verifier logs. In addition, the last two cases are covering the negative cases: when we shouldn't refine the bounds because the u64 and tnum overlap in at least two values. Signed-off-by: Paul Chaignon Link: https://lore.kernel.org/r/90d880c8cf587b9f7dc715d8961cd1b8111d01a8.1772225741.git.paul.chaignon@gmail.com Signed-off-by: Alexei Starovoitov [shung-hsi.yu: test for backported upstream commit efc11a667878 ("bpf: Improve bounds when tnum has a single possible value")] Signed-off-by: Shung-Hsi Yu Signed-off-by: Greg Kroah-Hartman

bpf: Fix u32/s32 bounds when ranges cross min/max boundary

2026-04-02T11:23:00+00:00

[ Upstream commit fbc7aef517d8765e4c425d2792409bb9bf2e1f13 ] Same as in __reg64_deduce_bounds(), refine s32/u32 ranges in __reg32_deduce_bounds() in the following situations: - s32 range crosses U32_MAX/0 boundary, positive part of the s32 range overlaps with u32 range: 0 U32_MAX | [xxxxxxxxxxxxxx u32 range xxxxxxxxxxxxxx] | |----------------------------|----------------------------| |xxxxx s32 range xxxxxxxxx] [xxxxxxx| 0 S32_MAX S32_MIN -1 - s32 range crosses U32_MAX/0 boundary, negative part of the s32 range overlaps with u32 range: 0 U32_MAX | [xxxxxxxxxxxxxx u32 range xxxxxxxxxxxxxx] | |----------------------------|----------------------------| |xxxxxxxxx] [xxxxxxxxxxxx s32 range | 0 S32_MAX S32_MIN -1 - No refinement if ranges overlap in two intervals. This helps for e.g. consider the following program: call %[bpf_get_prandom_u32]; w0 &= 0xffffffff; if w0 < 0x3 goto 1f; // on fall-through u32 range [3..U32_MAX] if w0 s> 0x1 goto 1f; // on fall-through s32 range [S32_MIN..1] if w0 s< 0x0 goto 1f; // range can be narrowed to [S32_MIN..-1] r10 = 0; 1: ...; The reg_bounds.c selftest is updated to incorporate identical logic, refinement based on non-overflowing range halves: ((x ∩ [0, smax]) ∩ (y ∩ [0, smax])) ∪ ((x ∩ [smin,-1]) ∩ (y ∩ [smin,-1])) Reported-by: Andrea Righi Reported-by: Emil Tsalapatis Closes: https://lore.kernel.org/bpf/aakqucg4vcujVwif@gpd4/T/ Reviewed-by: Emil Tsalapatis Acked-by: Shung-Hsi Yu Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/r/20260306-bpf-32-bit-range-overflow-v3-1-f7f67e060a6b@gmail.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

bpf: Fix exception exit lock checking for subprogs

2026-04-02T11:22:54+00:00

[ Upstream commit 6c2128505f61b504c79a20b89596feba61388112 ] process_bpf_exit_full() passes check_lock = !curframe to check_resource_leak(), which is false in cases when bpf_throw() is called from a static subprog. This makes check_resource_leak() to skip validation of active_rcu_locks, active_preempt_locks, and active_irq_id on exception exits from subprogs. At runtime bpf_throw() unwinds the stack via ORC without releasing any user-acquired locks, which may cause various issues as the result. Fix by setting check_lock = true for exception exits regardless of curframe, since exceptions bypass all intermediate frame cleanup. Update the error message prefix to "bpf_throw" for exception exits to distinguish them from normal BPF_EXIT. Fix reject_subprog_with_rcu_read_lock test which was previously passing for the wrong reason. Test program returned directly from the subprog call without closing the RCU section, so the error was triggered by the unclosed RCU lock on normal exit, not by bpf_throw. Update __msg annotations for affected tests to match the new "bpf_throw" error prefix. The spin_lock case is not affected because they are already checked [1] at the call site in do_check_insn() before bpf_throw can run. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/kernel/bpf/verifier.c?h=v7.0-rc4#n21098 Assisted-by: Claude:claude-opus-4-6 Fixes: f18b03fabaa9 ("bpf: Implement BPF exceptions") Signed-off-by: Ihor Solodrai Acked-by: Yonghong Song Acked-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260320000809.643798-1-ihor.solodrai@linux.dev Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

selftests/bpf: Avoid simplification of crafted bounds test

2026-03-12T11:10:03+00:00

[ Upstream commit 024cea2d647ed8ab942f19544b892d324dba42b4 ] The reg_bounds_crafted tests validate the verifier's range analysis logic. They focus on the actual ranges and thus ignore the tnum. As a consequence, they carry the assumption that the tested cases can be reproduced in userspace without using the tnum information. Unfortunately, the previous change the refinement logic breaks that assumption for one test case: (u64)2147483648 (u32) [4294967294; 0x100000000] The tested bytecode is shown below. Without our previous improvement, on the false branch of the condition, R7 is only known to have u64 range [0xfffffffe; 0x100000000]. With our improvement, and using the tnum information, we can deduce that R7 equals 0x100000000. 19: (bc) w0 = w6 ; R6=0x80000000 20: (bc) w0 = w7 ; R7=scalar(smin=umin=0xfffffffe,smax=umax=0x100000000,smin32=-2,smax32=0,var_off=(0x0; 0x1ffffffff)) 21: (be) if w6 <= w7 goto pc+3 ; R6=0x80000000 R7=0x100000000 R7's tnum is (0; 0x1ffffffff). On the false branch, regs_refine_cond_op refines R7's u32 range to [0; 0x7fffffff]. Then, __reg32_deduce_bounds refines the s32 range to 0 using u32 and finally also sets u32=0. From this, __reg_bound_offset improves the tnum to (0; 0x100000000). Finally, our previous patch uses this new tnum to deduce that it only intersect with u64=[0xfffffffe; 0x100000000] in a single value: 0x100000000. Because the verifier uses the tnum to reach this constant value, the selftest is unable to reproduce it by only simulating ranges. The solution implemented in this patch is to change the test case such that there is more than one overlap value between u64 and the tnum. The max. u64 value is thus changed from 0x100000000 to 0x300000000. Acked-by: Eduard Zingerman Signed-off-by: Paul Chaignon Link: https://lore.kernel.org/r/50641c6a7ef39520595dcafa605692427c1006ec.1772225741.git.paul.chaignon@gmail.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin