6.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Snehal Koukuntla <snehalreddy@xxxxxxxxxx>
commit f26a525b77e040d584e967369af1e018d2d59112 upstream.
When we share memory through FF-A and the description of the buffers
exceeds the size of the mapped buffer, the fragmentation API is used.
The fragmentation API allows specifying chunks of descriptors in subsequent
FF-A fragment calls and no upper limit has been established for this.
The entire memory region transferred is identified by a handle which can be
used to reclaim the transferred memory.
To be able to reclaim the memory, the description of the buffers has to fit
in the ffa_desc_buf.
Add a bounds check on the FF-A sharing path to prevent the memory reclaim
from failing.
Also do_ffa_mem_xfer() does not need __always_inline, except for the
BUILD_BUG_ON() aspect, which gets moved to a macro.
[maz: fixed the BUILD_BUG_ON() breakage with LLVM, thanks to Wei-Lin Chang
for the timely report]
Fixes: 634d90cf0ac65 ("KVM: arm64: Handle FFA_MEM_LEND calls from the host")
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Sebastian Ene <sebastianene@xxxxxxxxxx>
Signed-off-by: Snehal Koukuntla <snehalreddy@xxxxxxxxxx>
Reviewed-by: Oliver Upton <oliver.upton@xxxxxxxxx>
Link: https://lore.kernel.org/r/20240909180154.3267939-1-snehalreddy@xxxxxxxxxx
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/kvm/hyp/nvhe/ffa.c | 21 +++++++++++++++------
1 file changed, 15 insertions(+), 6 deletions(-)
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -423,9 +423,9 @@ out:
return;
}
-static __always_inline void do_ffa_mem_xfer(const u64 func_id,
- struct arm_smccc_res *res,
- struct kvm_cpu_context *ctxt)
+static void __do_ffa_mem_xfer(const u64 func_id,
+ struct arm_smccc_res *res,
+ struct kvm_cpu_context *ctxt)
{
DECLARE_REG(u32, len, ctxt, 1);
DECLARE_REG(u32, fraglen, ctxt, 2);
@@ -437,9 +437,6 @@ static __always_inline void do_ffa_mem_x
u32 offset, nr_ranges;
int ret = 0;
- BUILD_BUG_ON(func_id != FFA_FN64_MEM_SHARE &&
- func_id != FFA_FN64_MEM_LEND);
-
if (addr_mbz || npages_mbz || fraglen > len ||
fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) {
ret = FFA_RET_INVALID_PARAMETERS;
@@ -458,6 +455,11 @@ static __always_inline void do_ffa_mem_x
goto out_unlock;
}
+ if (len > ffa_desc_buf.len) {
+ ret = FFA_RET_NO_MEMORY;
+ goto out_unlock;
+ }
+
buf = hyp_buffers.tx;
memcpy(buf, host_buffers.tx, fraglen);
@@ -509,6 +511,13 @@ err_unshare:
goto out_unlock;
}
+#define do_ffa_mem_xfer(fid, res, ctxt) \
+ do { \
+ BUILD_BUG_ON((fid) != FFA_FN64_MEM_SHARE && \
+ (fid) != FFA_FN64_MEM_LEND); \
+ __do_ffa_mem_xfer((fid), (res), (ctxt)); \
+ } while (0);
+
static void do_ffa_mem_reclaim(struct arm_smccc_res *res,
struct kvm_cpu_context *ctxt)
{
