s390/mm: Fix in_atomic() handling in do_secure_storage_access()

Summary

In the Linux kernel, the following vulnerability has been resolved: s390/mm: Fix in_atomic() handling in do_secure_storage_access() Kernel user spaces accesses to not exported pages in atomic context incorrectly try to resolve the page fault. With debug options enabled call traces like this can be seen: BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1523 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 419074, name: qemu-system-s39 preempt_count: 1, expected: 0 RCU nest depth: 0, expected: 0 INFO: lockdep is turned off. Preemption disabled at: [<00000383ea47cfa2>] copy_page_from_iter_atomic+0xa2/0x8a0 CPU: 12 UID: 0 PID: 419074 Comm: qemu-system-s39 Tainted: G W 6.16.0-20250531.rc0.git0.69b3a602feac.63.fc42.s390x+debug #1 PREEMPT Tainted: [W]=WARN Hardware name: IBM 3931 A01 703 (LPAR) Call Trace: [<00000383e990d282>] dump_stack_lvl+0xa2/0xe8 [<00000383e99bf152>] __might_resched+0x292/0x2d0 [<00000383eaa7c374>] down_read+0x34/0x2d0 [<00000383e99432f8>] do_secure_storage_access+0x108/0x360 [<00000383eaa724b0>] __do_pgm_check+0x130/0x220 [<00000383eaa842e4>] pgm_check_handler+0x114/0x160 [<00000383ea47d028>] copy_page_from_iter_atomic+0x128/0x8a0 ([<00000383ea47d016>] copy_page_from_iter_atomic+0x116/0x8a0) [<00000383e9c45eae>] generic_perform_write+0x16e/0x310 [<00000383e9eb87f4>] ext4_buffered_write_iter+0x84/0x160 [<00000383e9da0de4>] vfs_write+0x1c4/0x460 [<00000383e9da123c>] ksys_write+0x7c/0x100 [<00000383eaa7284e>] __do_syscall+0x15e/0x280 [<00000383eaa8417e>] system_call+0x6e/0x90 INFO: lockdep is turned off. It is not allowed to take the mmap_lock while in atomic context. Therefore handle such a secure storage access fault as if the accessed page is not mapped: the uaccess function will return -EFAULT, and the caller has to deal with this. Usually this means that the access is retried in process context, which allows to resolve the page fault (or in this case export the page).

Timeline

1. Jul 25, 2025, 12:47 PM UTCCVE published
2. Oct 21, 2026, 12:37 PM UTCRecord last updated

Affected versions

• Linux Linux

  From 084ea4d611a3d00ee3930400b262240e10895900 · fixed in 9bcfbd58fc5a02777fed3e582f22503ef3289a43; From 084ea4d611a3d00ee3930400b262240e10895900 · fixed in 7aee3e5163cade3f4cf1cc0710dfbadb47f1ba84; From 084ea4d611a3d00ee3930400b262240e10895900 · fixed in d2e317dfd2d1fe416c77315d17c5d57dbe374915; From 084ea4d611a3d00ee3930400b262240e10895900 · fixed in 11709abccf93b08adde95ef313c300b0d4bc28f1

• Linux Linux

  5.7

• KernelLinux

  From 5.7.0 · fixed in 6.6.160; From 6.7.0 · fixed in 6.12.114; From 6.13.0 · fixed in 6.15.5

References 4