On plain ARMv8.0 devices (A53,A57,A73), strncpy_from_user_nofault() sometimes
fails to copy `filename_user` string correctly. This breaks su ofc, breaking
some apps like Termux (Play Store ver), ZArchiver and Root Explorer.
Apply the susfs patch
This does NOT seem to affect newer ARMv8.2+ CPUs (A75/A76 and newer)
My speculation? ARMv8.0 has weak speculation :)
here we replace `ksu_strncpy_from_user_nofault` with ksu_strncpy_from_user_retry:
- ksu_strncpy_from_user_nofault as fast-path copy
- fallback to access_ok to validate the pointer + strncpy_from_user
- manual null-termination just in case, as strncpy_from_user_nofault also does it
- remove that memset, seems useless as it is an strncpy, not strncat
basically, we retry on pagefualt
for usercopies, its not like were doing
memset(dest, 0, sizeof(dest));
strncat(dest, var, bytes);
that memset seems unneeded. instead we use strncpy itself to do proper
error and oob check and null term it after.
as for optimizations
- just return early if unauthorized
- commonized logic
- reduced duplication
Tested on:
- ARMv8.0 A73.a53, A57.a53, A53.a53
- ARMv8.2 A76.a55
Stale: tiann #2656
Co-authored-by: backslashxx <118538522+backslashxx@users.noreply.github.com>
Co-authored-by: ShirkNeko <109797057+ShirkNeko@users.noreply.github.com>
Co-authored-by: rsuntk <rsuntk@yukiprjkt.my.id>
Signed-off-by: ShirkNeko <109797057+ShirkNeko@users.noreply.github.com>
`ksu handles devpts with selinux lsm hook` - aviraxp
- no, not yet, but yes we can, thats a good idea.
This change tries to do that, so instead of hooking pts_unix98_lookup or
devpts_get_priv, we just watch security_inode_permission, if its devpts,
pass it along to the original handler.
EDIT: define devpts super magic if its undefined
- yeah I aint gonna include a conditional include of a header just for this
- while we can just fully remove the macro and inline, readability loss is bad
Co-authored-by: backslashxx <118538522+backslashxx@users.noreply.github.com>
* On newer kernel for some reason -Wno-strict-prototypes still does not fix the errors or warnings.
* To fix it, we just need to add void type.
Signed-off-by: rsuntk <rsuntk@yukiprjkt.my.id>
- In order to reduce the extra patch code and increase the rate of hunk succeed, we do not rename the symbols in KernelSU drvier but instead do it all in kernel/kallsym.c
- Make susfs_starts_with() global as it maybe useful in future
Co-authored-by: simonpunk <simonpunk2016@gmail.com>
- There must be a reason for doing [sizeof(su) + 1 ] wthin the syscall handlers in the original sucompat.c but I dont know why, but it does fix the bootloop for some devices.
- I will be shocked if sizeof(su) produces different result on different kernel, since it works on pixel8 and no bootloops whatsoever.
Co-authored-by: simonpunk <simonpunk2016@gmail.com>
1. kernel & KernelSU: More optimization for SUS_SU mode 2 (Experimental)
2. Always flag zygote spawned isolated service as non-root user app process and no su allowed process
3. Change susfs_fake_qstr_name, shorter length
4. KernelSU: SUS_SU: Initiate path with 0 and no memset is needed
Co-authored-by: simonpunk <simonpunk2016@gmail.com>
* Since it's interceptable from LSM Hook,
then we just need to remove ksu_handle_devpts and
make a decoy for it.
Signed-off-by: rsuntk <rsuntk@yukiprjkt.my.id>
On plain ARMv8.0 devices (A53,A57,A73), strncpy_from_user_nofault() sometimes
fails to copy `filename_user` string correctly. This breaks su ofc, breaking
some apps like Termux (Play Store ver), ZArchiver and Root Explorer.
This does NOT seem to affect newer ARMv8.2+ CPUs (A75/A76 and newer)
My speculation? ARMv8.0 has weak speculation :)
here we replace `strncpy_from_user_nofault()` with another routine:
- access_ok() to validate the pointer
- strncpy_from_user() to copy and validate string
- manual null-termination just in case, as strncpy_from_user_nofault also does it
- remove that memset, seems useless as it is an strncpy, not strncat
Kind of mimicking _nofault, but yes with this one we allow pagefaults.
Tested on:
- ARMv8.0 A73.a53, A57.a53, A53.a53
- ARMv8.2 A76.a55
Tested-by: iDead XD <rafifirdaus12bb@gmail.com>
Signed-off-by: backslashxx <118538522+backslashxx@users.noreply.github.com>
This is done like how vfs_read_hook, input_hook and execve_hook is disabled.
While this is not exactly the same thing, this CAN achieve the same results.
The complete disabling of all KernelSU hooks.
While this is likely unneeded, It keeps feature parity to non-kprobe builds.
adapted from upstream:
kernel: Allow to re-enable sucompat - tiann/KernelSU@4593ae8
Rejected: tiann/KernelSU#2506
Signed-off-by: backslashxx <118538522+backslashxx@users.noreply.github.com>
kernel/selinux: fix pointer mismatch with 32-bit ksud on 64-bit kernels
Since KernelSU Manager can now be built for 32-bit, theres this problematic
setup where userspace is 32-bit (armeabi-v7a) and kernel is 64bit (aarch64).
On 64-bit kernels with CONFIG_COMPAT=y, 32-bit userspace passes 32-bit pointers.
These values are interpreted as 64-bit pointers without proper casting and that
results in invalid or near-null memory access.
This patch adds proper compat-mode handling with the ff changes:
- introduce a dedicated struct (`sepol_compat_data`) using u32 fields
- use `compat_ptr()` to safely convert 32-bit user pointers to kernel pointers
- adding a runtime `ksu_is_compat` flag to dynamically select between struct layouts
This prevents a near-null pointer dereference when handling SELinux
policy updates from 32-bit ksud in a 64-bit kernel.
Truth table:
kernel 32 + ksud 32, struct is u32, no compat_ptr
kernel 64 + ksud 32, struct is u32, yes compat_ptr
kernel 64 + ksud 64, struct is u64, no compat_ptr
Preprocessor check
64BIT=y COMPAT=y: define both structs, select dynamically
64BIT=y COMPAT=n: struct u64
64BIT=n: struct u32
kernel/throne_tracker: we just uninstalled the manager, stop looking for it
When the manager UID disappears from packages.list, we correctly
invalidate it — good. But, in the very next breath, we start scanning
/data/app hoping to find it again?
This event is just unnecessary I/O, exactly when we should be doing less.
Apparently this causes hangups and stuckups which is REALLY noticeable
on Ultra-Legacy devices.
Skip the scan — we’ll catch the reinstall next time packages.list updates.
This is done like how vfs_read_hook, input_hook and execve_hook is disabled.
While this is not exactly the same thing, this CAN achieve the same results.
The complete disabling of all KernelSU hooks.
While this is likely unneeded, It keeps feature parity to non-kprobe builds.
adapted from upstream:
kernel: Allow to re-enable sucompat - 4593ae81c7
Rejected: https://github.com/tiann/KernelSU/pull/2506
Signed-off-by: backslashxx <118538522+backslashxx@users.noreply.github.com>
