From: Nicolas Bouchinet <nicolas.bouchinet@xxxxxxxxxxx>
Hi,
This patchset adds some bound checks to sysctls to avoid negative
value writes.
The patched sysctls were storing the result of the proc_dointvec
proc_handler into an unsigned int data. proc_dointvec being able to
parse negative value, and it return value being a signed int, this could
lead to undefined behaviors.
This has led to kernel crash in the past as described in commit
3b3376f222e3 ("sysctl.c: fix underflow value setting risk in vm_table")
They are now bounded between SYSCTL_ZERO and SYSCTL_INT_MAX.
The proc_handlers have thus been updated to proc_dointvec_minmax.
This patchset has been written over sysctl-testing branch [1].
See [2] for similar sysctl fixes currently in review.
[1]: https://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl.git/log/?h=sysctl-testing
[2]: https://lore.kernel.org/all/20250115132211.25400-1-nicolas.bouchinet@xxxxxxxxxxx/
Best regards,
Nicolas
---
Changes since v2:
https://lore.kernel.org/all/20250224095826.16458-1-nicolas.bouchinet@xxxxxxxxxxx/
* Detached patches 2/6, 4/6 and 5/6
* Changed coda_timeout type from unsigned long to unsigned int as
suggested by Joel Granados and Jan Harkes.
Changes since v1:
https://lore.kernel.org/all/20250127142014.37834-1-nicolas.bouchinet@xxxxxxxxxxx/
* Detached patches 1/9, 2/9 [3] and 3/9 [4]
* Adapted the cover-letter message to match the reduced patchset
[3]: https://lore.kernel.org/all/20250129170633.88574-1-nicolas.bouchinet@xxxxxxxxxxx/
[4]: https://lore.kernel.org/all/20250128103821.29745-1-nicolas.bouchinet@xxxxxxxxxxx/
---
Nicolas Bouchinet (3):
sysctl: Fixes idmap_cache_timeout bounds
sysctl/coda: Fixes timeout bounds
sysctl: Fixes max-user-freq bounds
drivers/char/hpet.c | 4 +++-
fs/coda/coda_int.h | 2 +-
fs/coda/sysctl.c | 4 +++-
fs/nfs/nfs4sysctl.c | 4 +++-
4 files changed, 10 insertions(+), 4 deletions(-)
--
2.48.1
