lib/decompressors: use real out buf size for gunzip with kernel
commit 2d3862d2 upstream. When loading x86 64bit kernel above 4GiB with patched grub2, got kernel gunzip error. | early console in decompress_kernel | decompress_kernel: | input: [0x807f2143b4-0x807ff61aee] | output: [0x807cc00000-0x807f3ea29b] 0x027ea29c: output_len | boot via startup_64 | KASLR using RDTSC... | new output: [0x46fe000000-0x470138cfff] 0x0338d000: output_run_size | decompress: [0x46fe000000-0x47007ea29b] <=== [0x807f2143b4-0x807ff61aee] | | Decompressing Linux... gz... | | uncompression error | | -- System halted the new buffer is at 0x46fe000000ULL, decompressor_gzip is using 0xffffffb901ffffff as out_len. gunzip in lib/zlib_inflate/inflate.c cap that len to 0x01ffffff and decompress fails later. We could hit this problem with crashkernel booting that uses kexec loading kernel above 4GiB. We have decompress_* support: 1. inbuf[]/outbuf[] for kernel preboot. 2. inbuf[]/flush() for initramfs 3. fill()/flush() for initrd. This bug only affect kernel preboot path that use outbuf[]. Add __decompress and take real out_buf_len for gunzip instead of guessing wrong buf size. Fixes: 1431574a (lib/decompressors: fix "no limit" output buffer length) Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Alexandre Courbot <acourbot@nvidia.com> Cc: Jon Medhurst <tixy@linaro.org> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Showing
Please register or sign in to comment