When a write happens it doesn't make sense to check perform checks on the input. Skip them. Whether a fixes tag is licensed is a bit of a gray area here but I'll add one for the socket validation part I added recently. Fixes: 16195d2c7dd2 ("coredump: validate socket name as it is written") Reported-by: Brad Spengler <brad.spengler@xxxxxxxxxxxxxx> Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx> --- fs/coredump.c | 4 ++++ fs/exec.c | 2 +- 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/coredump.c b/fs/coredump.c index 5dce257c67fc..60bc9685e149 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -1466,11 +1466,15 @@ static int proc_dostring_coredump(const struct ctl_table *table, int write, ssize_t retval; char old_core_pattern[CORENAME_MAX_SIZE]; + if (write) + return proc_dostring(table, write, buffer, lenp, ppos); + retval = strscpy(old_core_pattern, core_pattern, CORENAME_MAX_SIZE); error = proc_dostring(table, write, buffer, lenp, ppos); if (error) return error; + if (!check_coredump_socket()) { strscpy(core_pattern, old_core_pattern, retval + 1); return -EINVAL; diff --git a/fs/exec.c b/fs/exec.c index 2a1e5e4042a1..e861a4b7ffda 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -2048,7 +2048,7 @@ static int proc_dointvec_minmax_coredump(const struct ctl_table *table, int writ { int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos); - if (!error) + if (!error && !write) validate_coredump_safety(); return error; } -- 2.47.2