diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-04-08 13:18:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-04-08 13:18:57 -0700 |
| commit | 52f657e34d7b21b47434d9d8b26fa7f6778b63a0 (patch) | |
| tree | 17c82247d560acf441f7d08af34306455bd9aaf7 | |
| parent | 3036cd0d3328220a1858b1ab390be8b562774e8a (diff) | |
x86: shadow stacks: proper error handling for mmap lock
김영민 reports that shstk_pop_sigframe() doesn't check for errors from
mmap_read_lock_killable(), which is a silly oversight, and also shows
that we haven't marked those functions with "__must_check", which would
have immediately caught it.
So let's fix both issues.
Reported-by: 김영민 <osori@hspace.io>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | arch/x86/kernel/shstk.c | 3 | ||||
| -rw-r--r-- | include/linux/mmap_lock.h | 6 |
2 files changed, 5 insertions, 4 deletions
diff --git a/arch/x86/kernel/shstk.c b/arch/x86/kernel/shstk.c index 978232b6d48d..ff8edea8511b 100644 --- a/arch/x86/kernel/shstk.c +++ b/arch/x86/kernel/shstk.c @@ -351,7 +351,8 @@ static int shstk_pop_sigframe(unsigned long *ssp) need_to_check_vma = PAGE_ALIGN(*ssp) == *ssp; if (need_to_check_vma) - mmap_read_lock_killable(current->mm); + if (mmap_read_lock_killable(current->mm)) + return -EINTR; err = get_shstk_data(&token_addr, (unsigned long __user *)*ssp); if (unlikely(err)) diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h index 93eca48bc443..04b8f61ece5d 100644 --- a/include/linux/mmap_lock.h +++ b/include/linux/mmap_lock.h @@ -546,7 +546,7 @@ static inline void mmap_write_lock_nested(struct mm_struct *mm, int subclass) __mmap_lock_trace_acquire_returned(mm, true, true); } -static inline int mmap_write_lock_killable(struct mm_struct *mm) +static inline int __must_check mmap_write_lock_killable(struct mm_struct *mm) { int ret; @@ -593,7 +593,7 @@ static inline void mmap_read_lock(struct mm_struct *mm) __mmap_lock_trace_acquire_returned(mm, false, true); } -static inline int mmap_read_lock_killable(struct mm_struct *mm) +static inline int __must_check mmap_read_lock_killable(struct mm_struct *mm) { int ret; @@ -603,7 +603,7 @@ static inline int mmap_read_lock_killable(struct mm_struct *mm) return ret; } -static inline bool mmap_read_trylock(struct mm_struct *mm) +static inline bool __must_check mmap_read_trylock(struct mm_struct *mm) { bool ret; |