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authorIlya Leoshkevich <iii@linux.ibm.com>2020-12-30 02:15:01 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-12-30 02:36:49 +0300
commitf0bb29e8c4076444d32df00c8d32e169ceecf283 (patch)
tree2002d27ed28f309865bdb0cba2acd5fb68fefc49 /lib
parent36845663843fc59c5d794e3dc0641472e3e572da (diff)
downloadlinux-f0bb29e8c4076444d32df00c8d32e169ceecf283.tar.xz
lib/zlib: fix inflating zlib streams on s390
Decompressing zlib streams on s390 fails with "incorrect data check" error. Userspace zlib checks inflate_state.flags in order to byteswap checksums only for zlib streams, and s390 hardware inflate code, which was ported from there, tries to match this behavior. At the same time, kernel zlib does not use inflate_state.flags, so it contains essentially random values. For many use cases either zlib stream is zeroed out or checksum is not used, so this problem is masked, but at least SquashFS is still affected. Fix by always passing a checksum to and from the hardware as is, which matches zlib_inflate()'s expectations. Link: https://lkml.kernel.org/r/20201215155551.894884-1-iii@linux.ibm.com Fixes: 126196100063 ("lib/zlib: add s390 hardware support for kernel zlib_inflate") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Mikhail Zaslonko <zaslonko@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Mikhail Zaslonko <zaslonko@linux.ibm.com> Cc: <stable@vger.kernel.org> [5.6+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/zlib_dfltcc/dfltcc_inflate.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/lib/zlib_dfltcc/dfltcc_inflate.c b/lib/zlib_dfltcc/dfltcc_inflate.c
index db107016d29b..fb60b5a6a1cb 100644
--- a/lib/zlib_dfltcc/dfltcc_inflate.c
+++ b/lib/zlib_dfltcc/dfltcc_inflate.c
@@ -125,7 +125,7 @@ dfltcc_inflate_action dfltcc_inflate(
param->ho = (state->write - state->whave) & ((1 << HB_BITS) - 1);
if (param->hl)
param->nt = 0; /* Honor history for the first block */
- param->cv = state->flags ? REVERSE(state->check) : state->check;
+ param->cv = state->check;
/* Inflate */
do {
@@ -138,7 +138,7 @@ dfltcc_inflate_action dfltcc_inflate(
state->bits = param->sbb;
state->whave = param->hl;
state->write = (param->ho + param->hl) & ((1 << HB_BITS) - 1);
- state->check = state->flags ? REVERSE(param->cv) : param->cv;
+ state->check = param->cv;
if (cc == DFLTCC_CC_OP2_CORRUPT && param->oesc != 0) {
/* Report an error if stream is corrupted */
state->mode = BAD;