Linux: reject read/write mapping to immutable file only on VM_SHARED

Private read/write mapping can't be used to modify the mapped files, so
they will remain be immutable. Private read/write mappings are usually
used to load the data segment of executable files, rejecting them will
rendering immutable executable files to stop working.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: WHR <msl0000023508@gmail.com>
Closes #15344
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Low-power 2023-11-09 04:19:38 +08:00 committed by GitHub
parent 3a81bf4ad2
commit a160c153e2
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@ -4078,8 +4078,8 @@ zfs_map(struct inode *ip, offset_t off, caddr_t *addrp, size_t len,
if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
return (error);
if ((vm_flags & VM_WRITE) && (zp->z_pflags &
(ZFS_IMMUTABLE | ZFS_READONLY | ZFS_APPENDONLY))) {
if ((vm_flags & VM_WRITE) && (vm_flags & VM_SHARED) &&
(zp->z_pflags & (ZFS_IMMUTABLE | ZFS_READONLY | ZFS_APPENDONLY))) {
zfs_exit(zfsvfs, FTAG);
return (SET_ERROR(EPERM));
}