Description
In the Linux kernel, the following vulnerability has been resolved: csky: Fix a4/a5 restoration in syscall trace path The syscall trace path reloads syscall arguments from pt_regs before calling the syscall handler. On C-SKY ABIv2, the 5th and 6th syscall arguments are prepared as stack arguments before invoking syscallid. The current code adjusts sp before loading LSAVE_A4 and LSAVE_A5. Since those offsets are relative to the original pt_regs base, loading them after changing sp fetches the wrong slots. As a result, traced syscalls that use the 5th or 6th argument may receive corrupted arguments. This is visible with mmap2(), which takes six arguments. A small PTRACE_SYSCALL reproducer opens a file and maps one page with: mmap(NULL, 4096, PROT_READ | PROT_EXEC, MAP_PRIVATE, fd, 0) Before the fix, the traced child fails the mmap and exits with 12. After the fix, the mapping succeeds and the child exits with 0. Fix the trace path by loading a4/a5 from pt_regs before changing sp. Tested on: ck860f, linux-4.19.15, C-SKY abiv2
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
e0bbb53843b5fdfe464b099217e3b9d97e8a75d7 to < e9ae8e86eed68bea5d2670eadf61938a43bd2263affectede0bbb53843b5fdfe464b099217e3b9d97e8a75d7 to < 64e3ec7a71d3b715e2567f19f64207f04999bb0caffectede0bbb53843b5fdfe464b099217e3b9d97e8a75d7 to < 863fa63fd1491f201ac819f805a8db98d2a32c3daffectede0bbb53843b5fdfe464b099217e3b9d97e8a75d7 to < e71a3dc5b8d2ea4d9cfbdb135d6b7777de84212eaffectede0bbb53843b5fdfe464b099217e3b9d97e8a75d7 to < 31c81b376e5f058c7f2c94f69719cf7caec2fc3faffectede0bbb53843b5fdfe464b099217e3b9d97e8a75d7 to < a776afa89424570bfa637ebf812ca281a5732904affectede0bbb53843b5fdfe464b099217e3b9d97e8a75d7 to < 343aa5275484d627c921a42e8e115cae366be5deaffectede0bbb53843b5fdfe464b099217e3b9d97e8a75d7 to < abb81e5ce7d995baa41556b8125fa59e28ba3be8affected108681048cf728a8570e036c34ebd7daa43133b4affected3a5837c692918c229baf63fe7950965d27c48ac2affected5.4.47 to < 5.5affected5.6.19 to < 5.7affected
Linux Linux
Default version status: affected
5.7affected0 to < 5.7unaffected5.10.270 to ≤ 5.10.*unaffected5.15.221 to ≤ 5.15.*unaffected6.1.188 to ≤ 6.1.*unaffected6.6.157 to ≤ 6.6.*unaffected6.12.110 to ≤ 6.12.*unaffected6.18.52 to ≤ 6.18.*unaffected7.2.6 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/e9ae8e86eed68bea5d2670eadf61938a43bd2263 ↗
- https://git.kernel.org/stable/c/64e3ec7a71d3b715e2567f19f64207f04999bb0c ↗
- https://git.kernel.org/stable/c/863fa63fd1491f201ac819f805a8db98d2a32c3d ↗
- https://git.kernel.org/stable/c/e71a3dc5b8d2ea4d9cfbdb135d6b7777de84212e ↗
- https://git.kernel.org/stable/c/31c81b376e5f058c7f2c94f69719cf7caec2fc3f ↗
- https://git.kernel.org/stable/c/a776afa89424570bfa637ebf812ca281a5732904 ↗
- https://git.kernel.org/stable/c/343aa5275484d627c921a42e8e115cae366be5de ↗
- https://git.kernel.org/stable/c/abb81e5ce7d995baa41556b8125fa59e28ba3be8 ↗