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fixed multiple vulnerabilities in sysfn70 caused by absence of user addresses check

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git-svn-id: svn://kolibrios.org@8680 a494cfbc-eb01-0410-851d-a64ba20cac60
This commit is contained in:
Rustem Gimadutdinov (rgimad) 2021-04-24 21:16:55 +00:00
parent f8a8da3991
commit 7f4ba4d3e1
3 changed files with 95 additions and 3 deletions
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7
kernel/trunk/core/dll.inc
View File

@ -385,7 +385,12 @@ proc get_fileinfo stdcall, file_name:dword, info:dword
mov eax, 70
lea ebx, [cmd]
int 0x40
pushad
cld
call protect_from_terminate
call file_system_lfn
call unprotect_from_terminate
popad
ret
endp

4
kernel/trunk/core/syscall.inc
View File

@ -168,7 +168,7 @@ iglobal
dd syscall_move_window ; 67-Window move or resize
dd f68 ; 68-Some internal services
dd sys_debug_services ; 69-Debug
dd file_system_lfn ; 70-Common file system interface, version 2
dd syscall_file_system_lfn ; 70-Common file system interface, version 2
dd syscall_window_settings ; 71-Window settings
dd sys_sendwindowmsg ; 72-Send window message
dd blit_32 ; 73-blitter;
@ -178,7 +178,7 @@ iglobal
dd sys_posix ; posix support
dd undefined_syscall ; 78-free
dd undefined_syscall ; 79-free
dd fileSystemUnicode ; 80-File system interface for different encodings
dd syscall_fileSystemUnicode ; 80-File system interface for different encodings
times 255 - ( ($-servetable2) /4 ) dd undefined_syscall
dd sys_end ; -1-end application

87
kernel/trunk/fs/fs_lfn.inc
View File

@ -26,6 +26,93 @@ maxPathLength = 1000h
image_of_eax EQU esp+32
image_of_ebx EQU esp+20
; System function 70 security check
align 4
proc file_system_is_operation_safe stdcall, inf_struct_ptr: dword
; in:
; inf_struct_ptr = pointer to information structure was given to sysfn70
; out: ZF = 1 if operation is safe
; ZF = 0 if operation can cause kernel crash
push ebx ecx edx
xor ecx, ecx ; ecx - length of target buffer
mov ebx, [inf_struct_ptr]
mov edx, [ebx + 16] ; base of target buffer
cmp dword [ebx], 0 ; if 70.0
jnz .case1
mov ecx, dword [ebx + 12]
jmp .end_switch
.case1:
cmp dword [ebx], 1 ; if 70.1
jnz .case2_3
;mov ecx, 32
cmp dword [ebx + 8], 1 ; check encoding
jbe .case1_304 ; if encdoing <= 1 i.e cpp866
mov ecx, 560 ; if unicode then bdvk block len is 560 bytes
jmp .case1_end
.case1_304:
mov ecx, 304 ; if cp866 then bdvk block len is 304 bytes
.case1_end:
imul ecx, dword [ebx + 12] ; multiply bdvk length by their count
add ecx, 32 ; add result header len
jmp .end_switch
.case2_3:
cmp dword [ebx], 3
ja .case5 ; if subfn > 3
mov ecx, dword [ebx + 12]
jmp .end_switch
.case5:
cmp dword [ebx], 5
jnz .case6
mov ecx, 40
jmp .end_switch
.case6:
cmp dword [ebx], 6
jnz .switch_none
mov ecx, 32
jmp .end_switch
.switch_none:
mov ecx, 1
test ecx, ecx
jmp .ret
.end_switch:
;;
stdcall is_region_userspace, edx, ecx
.ret:
pop edx ecx ebx
ret
endp
syscall_fileSystemUnicode:
; in: ebx -> f.80 parameter structure
stdcall file_system_is_operation_safe, ebx
jnz @f
DEBUGF 1, "sysfn80 addr error\n"
mov dword [image_of_eax], ERROR_MEMORY_POINTER
ret
@@:
jmp fileSystemUnicode
syscall_file_system_lfn:
; in: ebx -> f.70 parameter structure
stdcall file_system_is_operation_safe, ebx
jnz @f
DEBUGF 1, "sysfn70 addr error\n"
mov dword [image_of_eax], ERROR_MEMORY_POINTER
ret
@@:
jmp file_system_lfn
; System function 70
file_system_lfn_protected: