Hi Mimi, On Tue, Nov 29, 2022 at 06:28:09AM -0500, Mimi Zohar wrote: > On Fri, 2022-11-25 at 16:57 +0100, Nicolas Bouchinet wrote: > > From: Nicolas Bouchinet <nicolas.bouchinet@xxxxxxxxxxx> > > > > Fixes a NULL pointer dereference occurring in the > > `evm_protected_xattr_common` function of the EVM LSM. The bug is > > triggered if a `inode_init_security` hook returns 0 without initializing > > the given `struct xattr` fields (which is the case of BPF) and if no > > other LSM overrides thoses fields after. This also leads to memory > > leaks. > > > > The `call_int_hook_xattr` macro has been inlined into the > > `security_inode_init_security` hook in order to check hooks return > > values and skip ones who doesn't init `xattrs`. > > > > Modify `evm_init_hmac` function to init the EVM hmac using every > > entry of the given xattr array. > > > > The `MAX_LSM_EVM_XATTR` value is now based on the security modules > > compiled in, which gives room for SMACK, SELinux, Apparmor, BPF and > > IMA/EVM security attributes. > > > > Changes the default return value of the `inode_init_security` hook > > definition to `-EOPNOTSUPP`. > > > > Changes the hook documentation to match the behavior of the LSMs using > > it (only xattr->value is initialised with kmalloc and thus is the only > > one that should be kfreed by the caller). > > > > Cc: roberto.sassu@xxxxxxxxxxxxxxx > > Signed-off-by: Nicolas Bouchinet <nicolas.bouchinet@xxxxxxxxxxx> > > What is the relationship between this patch and Roberto's patch set? > Roberto, if there is an overlap, then at minimum there should be a > Reported-by tag indicating that your patch set addresses a bug reported > by Nicolas. This patch fixes the EVM NULL pointer dereference I have reported, and additionally improves the stackability of this LSM hook. This latter improvement was originally addressed by Roberto's patchset, and thus I see no problem for my fix to be merged within his patchset. > > -- > thanks, > > Mimi > Thanks for your time, Nicolas Bouchinet
