Peter Zijlstra c69df06e4e perf/core: Fix deadlock in perf_mmap() failure path ... Ian noted that commit 77de62ad3d ("perf/core: Fix refcount bug and potential UAF in perf_mmap") would cause a deadlock due to event->mmap_mutex recursion. This happens because we're now calling perf_mmap_close() under mmap_mutex, while that function itself can also take mmap_mutex. Solve this by noting that perf_mmap_close() is far more complicated than we need at this particular point, since it deals with scenarios that cannot happen in this particular case. Replace the call to perf_mmap_close() with a very narrow undo for the case of first-exposure. If this is not the first mmap(), there is no race and it is fine to drop the lock and call perf_mmap_close() to handle to more complicated scenarios. Note: move the rb->mmap_user (namespace) handling into the rb init/free code such that it does not complicate the mmap handling. Fixes: 77de62ad3d ("perf/core: Fix refcount bug and potential UAF in perf_mmap") Reported-by: Ian Rogers <irogers@google.com> Closes: https://patch.msgid.link/CAP-5%3DfVJyVMZw%3DDqP53Kxg58nUmJ_0bxoaeOKAbC03BVc11HaA%40mail.gmail.com Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20260326112821.GK3738786@noisy.programming.kicks-ass.net		2026-05-05 12:47:20 +02:00
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callchain.c	perf: sched: Fix perf crash with new is_user_task() helper	2026-01-30 23:06:07 +01:00
core.c	perf/core: Fix deadlock in perf_mmap() failure path	2026-05-05 12:47:20 +02:00
hw_breakpoint_test.c	perf/hw_breakpoint: remove MODULE_LICENSE in non-modules	2023-04-13 13:13:52 -07:00
hw_breakpoint.c	Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL uses	2026-02-22 08:26:33 -08:00
internal.h	perf/core: Fix deadlock in perf_mmap() failure path	2026-05-05 12:47:20 +02:00
Makefile	perf/hw_breakpoint: Add KUnit test for constraints accounting	2022-08-30 10:56:20 +02:00
ring_buffer.c	perf/core: Fix deadlock in perf_mmap() failure path	2026-05-05 12:47:20 +02:00
uprobes.c	treewide: change inode->i_ino from unsigned long to u64	2026-03-06 14:31:28 +01:00