user/sven/linux.git/kernel, branch v6.16.1

perf/core: Prevent VMA split of buffer mappings

2025-08-15T14:39:31Z

commit b024d7b56c77191cde544f838debb7f8451cd0d6 upstream. The perf mmap code is careful about mmap()'ing the user page with the ringbuffer and additionally the auxiliary buffer, when the event supports it. Once the first mapping is established, subsequent mapping have to use the same offset and the same size in both cases. The reference counting for the ringbuffer and the auxiliary buffer depends on this being correct. Though perf does not prevent that a related mapping is split via mmap(2), munmap(2) or mremap(2). A split of a VMA results in perf_mmap_open() calls, which take reference counts, but then the subsequent perf_mmap_close() calls are not longer fulfilling the offset and size checks. This leads to reference count leaks. As perf already has the requirement for subsequent mappings to match the initial mapping, the obvious consequence is that VMA splits, caused by resizing of a mapping or partial unmapping, have to be prevented. Implement the vm_operations_struct::may_split() callback and return unconditionally -EINVAL. That ensures that the mapping offsets and sizes cannot be changed after the fact. Remapping to a different fixed address with the same size is still possible as it takes the references for the new mapping and drops those of the old mapping. Fixes: 45bfb2e50471 ("perf/core: Add AUX area to ring buffer for raw data streams") Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-27504 Signed-off-by: Thomas Gleixner Reviewed-by: Lorenzo Stoakes Acked-by: Arnaldo Carvalho de Melo Acked-by: Vlastimil Babka Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

perf/core: Handle buffer mapping fail correctly in perf_mmap()

2025-08-15T14:39:30Z

commit f74b9f4ba63ffdf597aaaa6cad7e284cb8e04820 upstream. After successful allocation of a buffer or a successful attachment to an existing buffer perf_mmap() tries to map the buffer read only into the page table. If that fails, the already set up page table entries are zapped, but the other perf specific side effects of that failure are not handled. The calling code just cleans up the VMA and does not invoke perf_mmap_close(). This leaks reference counts, corrupts user->vm accounting and also results in an unbalanced invocation of event::event_mapped(). Cure this by moving the event::event_mapped() invocation before the map_range() call so that on map_range() failure perf_mmap_close() can be invoked without causing an unbalanced event::event_unmapped() call. perf_mmap_close() undoes the reference counts and eventually frees buffers. Fixes: b709eb872e19 ("perf/core: map pages in advance") Signed-off-by: Thomas Gleixner Reviewed-by: Lorenzo Stoakes Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

perf/core: Exit early on perf_mmap() fail

2025-08-15T14:39:30Z

commit 07091aade394f690e7b655578140ef84d0e8d7b0 upstream. When perf_mmap() fails to allocate a buffer, it still invokes the event_mapped() callback of the related event. On X86 this might increase the perf_rdpmc_allowed reference counter. But nothing undoes this as perf_mmap_close() is never called in this case, which causes another reference count leak. Return early on failure to prevent that. Fixes: 1e0fb9ec679c ("perf/core: Add pmu callbacks to track event mapping and unmapping") Signed-off-by: Thomas Gleixner Reviewed-by: Lorenzo Stoakes Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

perf/core: Don't leak AUX buffer refcount on allocation failure

2025-08-15T14:39:30Z

commit 5468c0fbccbb9d156522c50832244a8b722374fb upstream. Failure of the AUX buffer allocation leaks the reference count. Set the reference count to 1 only when the allocation succeeds. Fixes: 45bfb2e50471 ("perf/core: Add AUX area to ring buffer for raw data streams") Signed-off-by: Thomas Gleixner Reviewed-by: Lorenzo Stoakes Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

perf/core: Preserve AUX buffer allocation failure result

2025-08-15T14:39:30Z

commit 54473e0ef849f44e5ee43e6d6746c27030c3825b upstream. A recent overhaul sets the return value to 0 unconditionally after the allocations, which causes reference count leaks and corrupts the user->vm accounting. Preserve the AUX buffer allocation failure return value, so that the subsequent code works correctly. Fixes: 0983593f32c4 ("perf/core: Lift event->mmap_mutex in perf_mmap()") Signed-off-by: Thomas Gleixner Reviewed-by: Lorenzo Stoakes Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

sched/psi: Fix psi_seq initialization

2025-08-15T14:39:21Z

[ Upstream commit 99b773d720aeea1ef2170dce5fcfa80649e26b78 ] With the seqcount moved out of the group into a global psi_seq, re-initializing the seqcount on group creation is causing seqcount corruption. Fixes: 570c8efd5eb7 ("sched/psi: Optimize psi_group_change() cpu_clock() usage") Reported-by: Chris Mason Suggested-by: Beata Michalska Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

ucount: fix atomic_long_inc_below() argument type

2025-08-15T14:39:17Z

[ Upstream commit f8cd9193b62e92ad25def5370ca8ea2bc7585381 ] The type of u argument of atomic_long_inc_below() should be long to avoid unwanted truncation to int. The patch fixes the wrong argument type of an internal function to prevent unwanted argument truncation. It fixes an internal locking primitive; it should not have any direct effect on userspace. Mark said : AFAICT there's no problem in practice because atomic_long_inc_below() : is only used by inc_ucount(), and it looks like the value is : constrained between 0 and INT_MAX. : : In inc_ucount() the limit value is taken from : user_namespace::ucount_max[], and AFAICT that's only written by : sysctls, to the table setup by setup_userns_sysctls(), where : UCOUNT_ENTRY() limits the value between 0 and INT_MAX. : : This is certainly a cleanup, but there might be no functional issue in : practice as above. Link: https://lkml.kernel.org/r/20250721174610.28361-1-ubizjak@gmail.com Fixes: f9c82a4ea89c ("Increase size of ucounts to atomic_long_t") Signed-off-by: Uros Bizjak Reviewed-by: "Eric W. Biederman" Cc: Sebastian Andrzej Siewior Cc: "Paul E. McKenney" Cc: Alexey Gladkov Cc: Roman Gushchin Cc: MengEn Sun Cc: "Thomas Weißschuh" Cc: Mark Rutland Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

uprobes: revert ref_ctr_offset in uprobe_unregister error path

2025-08-15T14:39:16Z

[ Upstream commit aa644c405291a419e92b112e2279c01c410e9a26 ] There's error path that could lead to inactive uprobe: 1) uprobe_register succeeds - updates instruction to int3 and changes ref_ctr from 0 to 1 2) uprobe_unregister fails - int3 stays in place, but ref_ctr is changed to 0 (it's not restored to 1 in the fail path) uprobe is leaked 3) another uprobe_register comes and re-uses the leaked uprobe and succeds - but int3 is already in place, so ref_ctr update is skipped and it stays 0 - uprobe CAN NOT be triggered now 4) uprobe_unregister fails because ref_ctr value is unexpected Fix this by reverting the updated ref_ctr value back to 1 in step 2), which is the case when uprobe_unregister fails (int3 stays in place), but we have already updated refctr. The new scenario will go as follows: 1) uprobe_register succeeds - updates instruction to int3 and changes ref_ctr from 0 to 1 2) uprobe_unregister fails - int3 stays in place and ref_ctr is reverted to 1.. uprobe is leaked 3) another uprobe_register comes and re-uses the leaked uprobe and succeds - but int3 is already in place, so ref_ctr update is skipped and it stays 1 - uprobe CAN be triggered now 4) uprobe_unregister succeeds Link: https://lkml.kernel.org/r/20250514101809.2010193-1-jolsa@kernel.org Fixes: 1cc33161a83d ("uprobes: Support SDT markers having reference count (semaphore)") Signed-off-by: Jiri Olsa Acked-by: David Hildenbrand Acked-by: Oleg Nesterov Suggested-by: Oleg Nesterov Cc: Andrii Nakryiko Cc: "Masami Hiramatsu (Google)" Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

bpf: Fix oob access in cgroup local storage

2025-08-15T14:39:14Z

[ Upstream commit abad3d0bad72a52137e0c350c59542d75ae4f513 ] Lonial reported that an out-of-bounds access in cgroup local storage can be crafted via tail calls. Given two programs each utilizing a cgroup local storage with a different value size, and one program doing a tail call into the other. The verifier will validate each of the indivial programs just fine. However, in the runtime context the bpf_cg_run_ctx holds an bpf_prog_array_item which contains the BPF program as well as any cgroup local storage flavor the program uses. Helpers such as bpf_get_local_storage() pick this up from the runtime context: ctx = container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx); storage = ctx->prog_item->cgroup_storage[stype]; if (stype == BPF_CGROUP_STORAGE_SHARED) ptr = &READ_ONCE(storage->buf)->data[0]; else ptr = this_cpu_ptr(storage->percpu_buf); For the second program which was called from the originally attached one, this means bpf_get_local_storage() will pick up the former program's map, not its own. With mismatching sizes, this can result in an unintended out-of-bounds access. To fix this issue, we need to extend bpf_map_owner with an array of storage_cookie[] to match on i) the exact maps from the original program if the second program was using bpf_get_local_storage(), or ii) allow the tail call combination if the second program was not using any of the cgroup local storage maps. Fixes: 7d9c3427894f ("bpf: Make cgroup storages shared between programs on the same cgroup") Reported-by: Lonial Con Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/r/20250730234733.530041-4-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

bpf: Move bpf map owner out of common struct

2025-08-15T14:39:14Z

[ Upstream commit fd1c98f0ef5cbcec842209776505d9e70d8fcd53 ] Given this is only relevant for BPF tail call maps, it is adding up space and penalizing other map types. We also need to extend this with further objects to track / compare to. Therefore, lets move this out into a separate structure and dynamically allocate it only for BPF tail call maps. Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/r/20250730234733.530041-2-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov Stable-dep-of: abad3d0bad72 ("bpf: Fix oob access in cgroup local storage") Signed-off-by: Sasha Levin