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| author |   Gabriel Krisman Bertazi <krisman@collabora.com> | 2020-03-16 20:45:06 -0400 |
|---|---|---|
| committer |   Richard Weinberger <richard@nod.at> | 2020-03-29 23:21:33 +0200 |
| commit | 6e682d53fc1ef73a169e2a5300326cb23abb32ee (patch) | |
| tree | a13449f41b0c5467b26d7e9f9e6b6ab9021e05ce /arch/um/drivers/ubd_kern.c | |
| parent | um: Fix overlapping ELF segments when statically linked (diff) | |
| download | linux-dev-6e682d53fc1ef73a169e2a5300326cb23abb32ee.tar.xz linux-dev-6e682d53fc1ef73a169e2a5300326cb23abb32ee.zip | |
um: ubd: Prevent buffer overrun on command completion
On the hypervisor side, when completing commands and the pipe is full,
we retry writing only the entries that failed, by offsetting
io_req_buffer, but we don't reduce the number of bytes written, which
can cause a buffer overrun of io_req_buffer, and write garbage to the
pipe.
Cc: Martyn Welch <martyn.welch@collabora.com>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um/drivers/ubd_kern.c')
| -rw-r--r-- | arch/um/drivers/ubd_kern.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index 247f95da057b..eca45ad2166c 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -1607,7 +1607,9 @@ int io_thread(void *arg) written = 0; do { - res = os_write_file(kernel_fd, ((char *) io_req_buffer) + written, n); + res = os_write_file(kernel_fd, + ((char *) io_req_buffer) + written, + n - written); if (res >= 0) { written += res; } |