3859a271a0
This marks many critical kernel structures for randomization. These are structures that have been targeted in the past in security exploits, or contain functions pointers, pointers to function pointer tables, lists, workqueues, ref-counters, credentials, permissions, or are otherwise sensitive. This initial list was extracted from Brad Spengler/PaX Team's code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Left out of this list is task_struct, which requires special handling and will be covered in a subsequent patch. Signed-off-by: Kees Cook <keescook@chromium.org>
82 lines
2.1 KiB
C
82 lines
2.1 KiB
C
#ifndef _LINUX_SHM_H_
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#define _LINUX_SHM_H_
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#include <linux/list.h>
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#include <asm/page.h>
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#include <uapi/linux/shm.h>
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#include <asm/shmparam.h>
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struct shmid_kernel /* private to the kernel */
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{
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struct kern_ipc_perm shm_perm;
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struct file *shm_file;
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unsigned long shm_nattch;
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unsigned long shm_segsz;
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time_t shm_atim;
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time_t shm_dtim;
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time_t shm_ctim;
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pid_t shm_cprid;
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pid_t shm_lprid;
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struct user_struct *mlock_user;
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/* The task created the shm object. NULL if the task is dead. */
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struct task_struct *shm_creator;
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struct list_head shm_clist; /* list by creator */
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} __randomize_layout;
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/* shm_mode upper byte flags */
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#define SHM_DEST 01000 /* segment will be destroyed on last detach */
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#define SHM_LOCKED 02000 /* segment will not be swapped */
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#define SHM_HUGETLB 04000 /* segment will use huge TLB pages */
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#define SHM_NORESERVE 010000 /* don't check for reservations */
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/* Bits [26:31] are reserved */
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/*
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* When SHM_HUGETLB is set bits [26:31] encode the log2 of the huge page size.
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* This gives us 6 bits, which is enough until someone invents 128 bit address
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* spaces.
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*
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* Assume these are all power of twos.
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* When 0 use the default page size.
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*/
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#define SHM_HUGE_SHIFT 26
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#define SHM_HUGE_MASK 0x3f
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#define SHM_HUGE_2MB (21 << SHM_HUGE_SHIFT)
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#define SHM_HUGE_1GB (30 << SHM_HUGE_SHIFT)
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#ifdef CONFIG_SYSVIPC
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struct sysv_shm {
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struct list_head shm_clist;
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};
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long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr,
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unsigned long shmlba);
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bool is_file_shm_hugepages(struct file *file);
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void exit_shm(struct task_struct *task);
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#define shm_init_task(task) INIT_LIST_HEAD(&(task)->sysvshm.shm_clist)
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#else
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struct sysv_shm {
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/* empty */
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};
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static inline long do_shmat(int shmid, char __user *shmaddr,
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int shmflg, unsigned long *addr,
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unsigned long shmlba)
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{
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return -ENOSYS;
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}
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static inline bool is_file_shm_hugepages(struct file *file)
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{
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return false;
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}
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static inline void exit_shm(struct task_struct *task)
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{
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}
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static inline void shm_init_task(struct task_struct *task)
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{
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}
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#endif
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#endif /* _LINUX_SHM_H_ */
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