CVE-2024-57838
s390/entry: Mark IRQ entries to fix stack depot warnings
We use these services and cookies to improve your user experience. You may opt out if you wish, however, this may limit some features on this site.
Please see our statement on Data Privacy.
s390/entry: Mark IRQ entries to fix stack depot warnings
In the Linux kernel, the following vulnerability has been resolved: s390/entry: Mark IRQ entries to fix stack depot warnings The stack depot filters out everything outside of the top interrupt context as an uninteresting or irrelevant part of the stack traces. This helps with stack trace de-duplication, avoiding an explosion of saved stack traces that share the same IRQ context code path but originate from different randomly interrupted points, eventually exhausting the stack depot. Filtering uses in_irqentry_text() to identify functions within the .irqentry.text and .softirqentry.text sections, which then become the last stack trace entries being saved. While __do_softirq() is placed into the .softirqentry.text section by common code, populating .irqentry.text is architecture-specific. Currently, the .irqentry.text section on s390 is empty, which prevents stack depot filtering and de-duplication and could result in warnings like: Stack depot reached limit capacity WARNING: CPU: 0 PID: 286113 at lib/stackdepot.c:252 depot_alloc_stack+0x39a/0x3c8 with PREEMPT and KASAN enabled. Fix this by moving the IO/EXT interrupt handlers from .kprobes.text into the .irqentry.text section and updating the kprobes blacklist to include the .irqentry.text section. This is done only for asynchronous interrupts and explicitly not for program checks, which are synchronous and where the context beyond the program check is important to preserve. Despite machine checks being somewhat in between, they are extremely rare, and preserving context when possible is also of value. SVCs and Restart Interrupts are not relevant, one being always at the boundary to user space and the other being a one-time thing. IRQ entries filtering is also optionally used in ftrace function graph, where the same logic applies.
Reserved 2025-01-11 | Published 2025-01-11 | Updated 2025-01-20 | Assigner Linuxgit.kernel.org/...c/ca687fdce5b95f84d91d6e36ac77047771eb3dfc
git.kernel.org/...c/5bb7a2c3afcf8732dc65ea49c09147b07da1d993
git.kernel.org/...c/1af22528fee8072b7adc007b8ca49cc4ea62689e
git.kernel.org/...c/473ffae3030188f1c6b80e1b3631a26b4adf7b32
git.kernel.org/...c/45c9f2b856a075a34873d00788d2e8a250c1effd
Support options
