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[PATCH OLK-6.6] bpf: Fix undefined behavior in interpreter sdiv/smod for INT_MIN
by Pu Lehui 24 Apr '26

24 Apr '26

From: Jenny Guanni Qu <qguanni(a)gmail.com> stable inclusion from stable-v6.6.131 commit 694ea55f1b1c74f9942d91ec366ae9e822422e42 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/14258 CVE: CVE-2026-31525 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- [ Upstream commit c77b30bd1dcb61f66c640ff7d2757816210c7cb0 ] The BPF interpreter's signed 32-bit division and modulo handlers use the kernel abs() macro on s32 operands. The abs() macro documentation (include/linux/math.h) explicitly states the result is undefined when the input is the type minimum. When DST contains S32_MIN (0x80000000), abs((s32)DST) triggers undefined behavior and returns S32_MIN unchanged on arm64/x86. This value is then sign-extended to u64 as 0xFFFFFFFF80000000, causing do_div() to compute the wrong result. The verifier's abstract interpretation (scalar32_min_max_sdiv) computes the mathematically correct result for range tracking, creating a verifier/interpreter mismatch that can be exploited for out-of-bounds map value access. Introduce abs_s32() which handles S32_MIN correctly by casting to u32 before negating, avoiding signed overflow entirely. Replace all 8 abs((s32)...) call sites in the interpreter's sdiv32/smod32 handlers. s32 is the only affected case -- the s64 division/modulo handlers do not use abs(). Fixes: ec0e2da95f72 ("bpf: Support new signed div/mod instructions.") Acked-by: Yonghong Song <yonghong.song(a)linux.dev> Acked-by: Mykyta Yatsenko <yatsenko(a)meta.com> Signed-off-by: Jenny Guanni Qu <qguanni(a)gmail.com> Link: https://lore.kernel.org/r/20260311011116.2108005-2-qguanni@gmail.com Signed-off-by: Alexei Starovoitov <ast(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Pu Lehui <pulehui(a)huawei.com> --- kernel/bpf/core.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 72a7503a59d0..e9ca3e36783e 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -1668,6 +1668,12 @@ bool bpf_opcode_in_insntable(u8 code) } #ifndef CONFIG_BPF_JIT_ALWAYS_ON +/* Absolute value of s32 without undefined behavior for S32_MIN */ +static u32 abs_s32(s32 x) +{ + return x >= 0 ? (u32)x : -(u32)x; +} + /** * ___bpf_prog_run - run eBPF program on a given context * @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers @@ -1832,8 +1838,8 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn) DST = do_div(AX, (u32) SRC); break; case 1: - AX = abs((s32)DST); - AX = do_div(AX, abs((s32)SRC)); + AX = abs_s32((s32)DST); + AX = do_div(AX, abs_s32((s32)SRC)); if ((s32)DST < 0) DST = (u32)-AX; else @@ -1860,8 +1866,8 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn) DST = do_div(AX, (u32) IMM); break; case 1: - AX = abs((s32)DST); - AX = do_div(AX, abs((s32)IMM)); + AX = abs_s32((s32)DST); + AX = do_div(AX, abs_s32((s32)IMM)); if ((s32)DST < 0) DST = (u32)-AX; else @@ -1887,8 +1893,8 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn) DST = (u32) AX; break; case 1: - AX = abs((s32)DST); - do_div(AX, abs((s32)SRC)); + AX = abs_s32((s32)DST); + do_div(AX, abs_s32((s32)SRC)); if (((s32)DST < 0) == ((s32)SRC < 0)) DST = (u32)AX; else @@ -1914,8 +1920,8 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn) DST = (u32) AX; break; case 1: - AX = abs((s32)DST); - do_div(AX, abs((s32)IMM)); + AX = abs_s32((s32)DST); + do_div(AX, abs_s32((s32)IMM)); if (((s32)DST < 0) == ((s32)IMM < 0)) DST = (u32)AX; else -- 2.34.1

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[PATCH OLK-6.6 0/3] Fix CVE-2026-31528
by Luo Gengkun 23 Apr '26

23 Apr '26

Peter Zijlstra (2): perf: Extract a few helpers perf: Make sure to use pmu_ctx->pmu for groups Peter Zijlstra (Intel) (1): perf: Avoid the read if the count is already updated include/linux/perf_event.h | 8 +++- kernel/events/core.c | 91 +++++++++++++++++++------------------ kernel/events/ring_buffer.c | 1 + 3 files changed, 54 insertions(+), 46 deletions(-) -- 2.34.1

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[PATCH OLK-6.6 0/1] Fix CVE-2026-31467
by Hongbo Li 23 Apr '26

23 Apr '26

Fix CVE-2026-31467. Jiucheng Xu (1): erofs: add GFP_NOIO in the bio completion if needed fs/erofs/zdata.c | 3 +++ 1 file changed, 3 insertions(+) -- 2.34.1

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[PATCH OLK-6.6] sched/ebpf: Fix bpf_sched_set_task_prefer_nid()
by Hui Tang 23 Apr '26

23 Apr '26

hulk inclusion category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/9010 ---------------------------------------- The current bpf_sched_set_task_prefer_nid() passes the full node mask directly to set_prefer_cpus_ptr(), which may result in preferred CPUs being outside of task->cpus_ptr. In such cases, the scheduler will ignore the preferred CPUs completely, causing the preferred node setting to NOT work at all. Fix this by computing the intersection between task->cpus_ptr and cpumask_of_node(nid), ensuring the resulting preferred mask is a subset of the task's allowed CPUs. Fixes: 4e47cb331dc0 ("sched/ebpf: Add kfunc to set the preferred NUMA node for the task") Signed-off-by: Hui Tang <tanghui20(a)huawei.com> --- kernel/sched/bpf_sched.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/sched/bpf_sched.c b/kernel/sched/bpf_sched.c index 6849a58439b2..ffe13eed601c 100644 --- a/kernel/sched/bpf_sched.c +++ b/kernel/sched/bpf_sched.c @@ -212,13 +212,16 @@ __bpf_kfunc long bpf_sched_tag_of_entity(struct sched_entity *se) __bpf_kfunc int bpf_sched_set_task_prefer_nid(struct task_struct *task, int nid) { + cpumask_t mask; + if (!task) return -EINVAL; if ((unsigned int)nid >= nr_node_ids) return -EINVAL; - return set_prefer_cpus_ptr(task, cpumask_of_node(nid)); + cpumask_and(&mask, task->cpus_ptr, cpumask_of_node(nid)); + return set_prefer_cpus_ptr(task, &mask); } BTF_SET8_START(sched_task_kfunc_btf_ids) -- 2.34.1

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[PATCH OLK-6.6] sched/ebpf: Fix bpf_sched_set_task_prefer_nid()
by Hui Tang 23 Apr '26

23 Apr '26

hulk inclusion category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/9010 ---------------------------------------- The current bpf_sched_set_task_prefer_nid() passes the full node mask directly to set_prefer_cpus_ptr(), which may result in preferred CPUs being outside of task->cpus_ptr. In such cases, the scheduler will ignore the preferred CPUs completely, causing the preferred node setting to NOT work at all. Fix this by computing the intersection between task->cpus_ptr and cpumask_of_node(nid), ensuring the resulting preferred mask is a subset of the task's allowed CPUs. Fixes: 4e47cb331dc0b ("sched/ebpf: Add kfunc to set the preferred...") Signed-off-by: Hui Tang <tanghui20(a)huawei.com> --- kernel/sched/bpf_sched.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/sched/bpf_sched.c b/kernel/sched/bpf_sched.c index 6849a58439b2..ffe13eed601c 100644 --- a/kernel/sched/bpf_sched.c +++ b/kernel/sched/bpf_sched.c @@ -212,13 +212,16 @@ __bpf_kfunc long bpf_sched_tag_of_entity(struct sched_entity *se) __bpf_kfunc int bpf_sched_set_task_prefer_nid(struct task_struct *task, int nid) { + cpumask_t mask; + if (!task) return -EINVAL; if ((unsigned int)nid >= nr_node_ids) return -EINVAL; - return set_prefer_cpus_ptr(task, cpumask_of_node(nid)); + cpumask_and(&mask, task->cpus_ptr, cpumask_of_node(nid)); + return set_prefer_cpus_ptr(task, &mask); } BTF_SET8_START(sched_task_kfunc_btf_ids) -- 2.34.1

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[OLK-6.6] sched/ebpf: Fix bpf_sched_set_task_prefer_nid()
by Hui Tang 23 Apr '26

23 Apr '26

hulk inclusion category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/9010 ---------------------------------------- The current bpf_sched_set_task_prefer_nid() passes the full node mask directly to set_prefer_cpus_ptr(), which may result in preferred CPUs being outside of task->cpus_ptr. In such cases, the scheduler will ignore the preferred CPUs completely, causing the preferred node setting to NOT work at all. Fix this by computing the intersection between task->cpus_ptr and cpumask_of_node(nid), ensuring the resulting preferred mask is a subset of the task's allowed CPUs. Fixes: 4e47cb331dc0b ("sched/ebpf: Add kfunc to set the preferred...") Signed-off-by: Hui Tang <tanghui20(a)huawei.com> --- kernel/sched/bpf_sched.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/sched/bpf_sched.c b/kernel/sched/bpf_sched.c index 6849a58439b2..ffe13eed601c 100644 --- a/kernel/sched/bpf_sched.c +++ b/kernel/sched/bpf_sched.c @@ -212,13 +212,16 @@ __bpf_kfunc long bpf_sched_tag_of_entity(struct sched_entity *se) __bpf_kfunc int bpf_sched_set_task_prefer_nid(struct task_struct *task, int nid) { + cpumask_t mask; + if (!task) return -EINVAL; if ((unsigned int)nid >= nr_node_ids) return -EINVAL; - return set_prefer_cpus_ptr(task, cpumask_of_node(nid)); + cpumask_and(&mask, task->cpus_ptr, cpumask_of_node(nid)); + return set_prefer_cpus_ptr(task, &mask); } BTF_SET8_START(sched_task_kfunc_btf_ids) -- 2.34.1

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[PATCH v2 OLK-6.6 0/7] fix CVE-2026-31398
by Wupeng Ma 22 Apr '26

22 Apr '26

Fix CVE-2026-31398. David Hildenbrand (4): mm: convert FPB_IGNORE_* into FPB_RESPECT_* mm: smaller folio_pte_batch() improvements mm: split folio_pte_batch() into folio_pte_batch() and folio_pte_batch_flags() mm: remove boolean output parameters from folio_pte_batch_ext() Dev Jain (2): mm: introduce FPB_RESPECT_WRITE for PTE batching infrastructure mm/rmap: fix incorrect pte restoration for lazyfree folios Petr Vaněk (1): mm: fix folio_pte_batch() on XEN PV mm/internal.h | 151 +++++++++++++++++++++++++++---------------------- mm/madvise.c | 27 ++------- mm/memory.c | 21 +++---- mm/mempolicy.c | 5 +- mm/mremap.c | 4 +- mm/rmap.c | 11 +++- mm/util.c | 29 ++++++++++ 7 files changed, 135 insertions(+), 113 deletions(-) -- 2.43.0

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[PATCH OLK-6.6 v2 0/3] mainline bpf patch
by Pu Lehui 22 Apr '26

22 Apr '26

Daniel Borkmann (1): bpf: Fix incorrect pruning due to atomic fetch precision tracking Qi Tang (1): bpf: reject direct access to nullable PTR_TO_BUF pointers Varun R Mallya (1): bpf: Reject sleepable kprobe_multi programs at attach time kernel/bpf/verifier.c | 28 ++++++++++++++++++++++++---- kernel/trace/bpf_trace.c | 4 ++++ 2 files changed, 28 insertions(+), 4 deletions(-) -- 2.34.1

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[PATCH OLK-6.6 0/3] mainline patch for bpf
by Pu Lehui 22 Apr '26

22 Apr '26

Daniel Borkmann (1): bpf: Fix incorrect pruning due to atomic fetch precision tracking Qi Tang (1): bpf: reject direct access to nullable PTR_TO_BUF pointers Varun R Mallya (1): bpf: Reject sleepable kprobe_multi programs at attach time kernel/bpf/verifier.c | 28 ++++++++++++++++++++++++---- kernel/trace/bpf_trace.c | 4 ++++ 2 files changed, 28 insertions(+), 4 deletions(-) -- 2.34.1

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[PATCH OLK-6.6] bpf: Reject sleepable kprobe_multi programs at attach time
by Pu Lehui 22 Apr '26

22 Apr '26

From: Varun R Mallya <varunrmallya(a)gmail.com> mainline inclusion from mainline-v7.0-rc7 commit eb7024bfcc5f68ed11ed9dd4891a3073c15f04a8 category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/9004 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- kprobe.multi programs run in atomic/RCU context and cannot sleep. However, bpf_kprobe_multi_link_attach() did not validate whether the program being attached had the sleepable flag set, allowing sleepable helpers such as bpf_copy_from_user() to be invoked from a non-sleepable context. This causes a "sleeping function called from invalid context" splat: BUG: sleeping function called from invalid context at ./include/linux/uaccess.h:169 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1787, name: sudo preempt_count: 1, expected: 0 RCU nest depth: 2, expected: 0 Fix this by rejecting sleepable programs early in bpf_kprobe_multi_link_attach(), before any further processing. Fixes: 0dcac2725406 ("bpf: Add multi kprobe link") Signed-off-by: Varun R Mallya <varunrmallya(a)gmail.com> Acked-by: Kumar Kartikeya Dwivedi <memxor(a)gmail.com> Acked-by: Leon Hwang <leon.hwang(a)linux.dev> Acked-by: Jiri Olsa <jolsa(a)kernel.org> Link: https://lore.kernel.org/r/20260401191126.440683-1-varunrmallya@gmail.com Signed-off-by: Alexei Starovoitov <ast(a)kernel.org> Conflicts: kernel/trace/bpf_trace.c [ctx conflicts] Signed-off-by: Pu Lehui <pulehui(a)huawei.com> --- kernel/trace/bpf_trace.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 50556b239023..1cdb832b9be5 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2901,6 +2901,10 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr if (sizeof(u64) != sizeof(void *)) return -EOPNOTSUPP; + /* kprobe_multi is not allowed to be sleepable. */ + if (prog->sleepable) + return -EINVAL; + if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI) return -EINVAL; -- 2.34.1

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