From 5bdb91f78125e565831a08088799aaa0dc2bb3ad Mon Sep 17 00:00:00 2001 From: Eric Farman Date: Tue, 28 Jul 2026 11:30:13 +0800 Subject: [PATCH] s390/vfio_ccw: Free all memory if cp_init() fails ANBZ: #44669 commit 74186c2968f8f756ac3226b545b598457c910c75 upstream. s390/vfio_ccw: Free all memory if cp_init() fails The routine cp_free() is called to unpin/free any memory once an I/O is completed successfully, or if cp_prefetch() fails. But if cp_init() fails, and cp->initialized is not enabled, the same routine cannot be used to free all the memory. An attempt to address this exists in ccwchain_handle_ccw(), where a single call to ccwchain_free() is made for the currently-processed CCW segment. But this will leak other segments (created as a result of a Transfer in Channel) that had been allocated as part of the same channel program. Address this by performing the cleanup outside of the recursive ccwchain_handle_ccw()/ccwchain_loop_tic() logic. Fixes: 8b515be512a2 ("vfio-ccw: Fix memory leak and don't call cp_free in cp_init") Cc: stable@vger.kernel.org Reviewed-by: Farhan Ali Reviewed-by: Matthew Rosato Signed-off-by: Eric Farman Signed-off-by: Christian Borntraeger Fixes: CVE-2026-80555 Assisted-by: PatchPilot Signed-off-by: Xunlei Pang --- drivers/s390/cio/vfio_ccw_cp.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index aafd66305ead..19c6a53bccfb 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -452,9 +452,6 @@ static int ccwchain_handle_ccw(u32 cda, struct channel_program *cp) /* Loop for tics on this new chain. */ ret = ccwchain_loop_tic(chain, cp); - if (ret) - ccwchain_free(chain); - return ret; } @@ -483,6 +480,23 @@ static int ccwchain_loop_tic(struct ccwchain *chain, struct channel_program *cp) return 0; } +static int ccwchain_build_ccws(dma32_t cda, struct channel_program *cp) +{ + struct ccwchain *chain, *temp; + int ret; + + ret = ccwchain_handle_ccw(cda, cp); + + if (ret) { + /* Cleanup if an error occurred */ + list_for_each_entry_safe(chain, temp, &cp->ccwchain_list, next) { + ccwchain_free(chain); + } + } + + return ret; +} + static int ccwchain_fetch_tic(struct ccw1 *ccw, struct channel_program *cp) { @@ -729,7 +743,7 @@ int cp_init(struct channel_program *cp, union orb *orb) memcpy(&cp->orb, orb, sizeof(*orb)); /* Build a ccwchain for the first CCW segment */ - ret = ccwchain_handle_ccw(orb->cmd.cpa, cp); + ret = ccwchain_build_ccws(orb->cmd.cpa, cp); if (!ret) cp->initialized = true; -- Gitee