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| author | Duoming Zhou <duoming@zju.edu.cn> | 2022-10-02 07:07:09 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-11-25 19:36:49 +0300 |
| commit | 3bded46232d732ad1951601422ee5c13b1d93bda (patch) | |
| tree | cd50534786b993312fd8861f41dab21debaa95b2 | |
| parent | 289c86becdac8d502923c8abb4a174319aa0fe4b (diff) | |
| download | linux-3bded46232d732ad1951601422ee5c13b1d93bda.tar.xz | |
tty: n_gsm: fix sleep-in-atomic-context bug in gsm_control_send
[ Upstream commit 7b7dfe4833c70a11cdfa51b38705103bd31eddaa ]
The function gsm_dlci_t1() is a timer handler that runs in an
atomic context, but it calls "kzalloc(..., GFP_KERNEL)" that
may sleep. As a result, the sleep-in-atomic-context bug will
happen. The process is shown below:
gsm_dlci_t1()
gsm_dlci_open()
gsm_modem_update()
gsm_modem_upd_via_msc()
gsm_control_send()
kzalloc(sizeof(.., GFP_KERNEL) //may sleep
This patch changes the gfp_t parameter of kzalloc() from GFP_KERNEL to
GFP_ATOMIC in order to mitigate the bug.
Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Link: https://lore.kernel.org/r/20221002040709.27849-1-duoming@zju.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/tty/n_gsm.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 1d50f3ab4e5a..97f6860c911e 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -1425,7 +1425,7 @@ static struct gsm_control *gsm_control_send(struct gsm_mux *gsm, unsigned int command, u8 *data, int clen) { struct gsm_control *ctrl = kzalloc(sizeof(struct gsm_control), - GFP_KERNEL); + GFP_ATOMIC); unsigned long flags; if (ctrl == NULL) return NULL; |